5-24-10M LXBRARY, campus. / TEXAS AGRICULTURAL EXPERIMENT STATIIIN AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS W. B. BIZZELL, President I TBULLETINHNO. 320 - MARCH, 1924 DIVISION OF ANIMAL INDUSTRY THE INFLUENCE OF INDIVIDUALITY, AGE AND SEASON UPON THE WEIGHTS OF FLEECES PRODUCED BY ANGORA GOATS UNDER RANGE CONDITIONS. qu- irfififijl-GP’ I Q $ “It!” k/TLIQ\|\\.$|»,'IIIIJ;IIII|I~QTE I AG JIII!"'II"III.'.‘;':IHIM .~;il:=ll!!bli_ L l _ ;..-.~1.~-.1.i i" CA7‘ QW£~B@~E ca? TERAR r E '2' _ y ‘a 5,.‘ N, l. :5 w v ,v > ~ . , ._ ____. _____.i< ___. ____ a; - B. YOUNGBLOOD, Director COLLEGE STATION, BRAZOS COUNTY, TEXAS STATION STAFFT AGRONOMY : ADMINISTRATION : B. YOUNGBLOOD, M. S., Ph. D., Director A. B. CONNER, M. S., Vice-Director A. H. LEIDIGH, M. S., Assistant Director CHAS. A. FELKER, Chief Clerk A. S. WARE, Secretary M. P. HOLLEMAN, J R., Ass’t. Chief Clerk J. M. SCHAEDEL, Executive Assistant VETERINARY SCIENCE: *M. FRANCIS, D. V. M., Chief of Division H. SCHMIDT, D. V. M., Veterinarian V. J. BRAUNER, D. V. M., Veterinarian CHEMISTRY: G. S. FRAPS, Ph. D., Chief of Division; State Chemist ~ S. E. ASBURY, M. S., Assistant Chemist‘ W. H. WALKER, Assistant Chemist J. E. TEAGUE, B. S., Assistant Chemist J. K. BLUM, B. S., Assistant Chemist H. STANFORD, B. S., Assistant Chemist K. KITSUTA, M. S., Assistant Chemist HORTI C ULTURE : ' A. T. POTTS, M. S., M. S. C., Chief of Division; Citriculturist ANIMAL INDUSTRY: J. M. JONES, A. M., Chief of Division; Sheep and Goats J. L. LUSH, Ph. D., Animal Husbandman, Animal Breeding G. R. WARREN, B. S., Swine Husbandman R. M. SHERWOOD, B. S., Poultry Hus- bandman J. J. HUNT, Wool Grader ENTOMOLOGY: F. L. THOMAS, Ph. D., Chief of Division; State Entomologist H. J. REINHARD, B. S., Entomologist; Cotton Insects h. B. PARKS, P- S., Apiculturist (San Antonio) A. H. ALEX, B. S., Qneen Breeder (San Antonio) C. S. RUDE, B. S., Chief Foul Brood Inspector W. R. JORDAN, B. S., Apiary Inspector E. B. REYNOLDS, M. S., Chief of Divisiolij Soil Fertility ‘_ A. B. CONNER, M. S., AgronomisLGrain " Sorghums A. H. LEIDIGH, M. S., Agronomist, Small Grains G. N. STROMAN, Ph. D., Agronomist, Cotton Breeding C. H. MAHONEY, B. S., Assistant in Cotton Breeding PLANT PATHOLOGY AND PHYSIOLOGY: J. J. TAUBENHAUS, Ph. D., Chief of Division FARM AND RANCH ECONOMICS: L. P. GABBARD, M. S., Chief of Division B. YOUNGBLOOD, M. S., Ph .D., Farm and Ranch Economist V. L. CORY, M. SI, Grazing Research Botanist (Sonora) " REA, B. S. Assistant in Farm and Ranch Economics SOIL SURVEY: **W. T. CARTER, B. S., Chief of Divis- ion; Soil Surveyor H. W. HAWKER, Soil Surveyor E. H. TEMPLIN, B. S., Soil Surveyor BOTANY: H. NESS, M. S., Chief of Division PUBLICATIONS: A. D. JACKSON, Chief of Division STATE APICULTURAL RESEARCH LABORATORY: (San Antonio, Bexar County) H. B. PARKS, B. S., Apiculturist in Charge A H ALEX, B. S., Queen Breeder MAIN STATION FARM: D. T. KILLOUGH, B. S., Superintendent FEED CONTROL SERVICE: B. YOUNGBLOOD, M. S., Ph. D., Director ‘ . F. D. FULLER, M. S., Chief of Division '. S. D. PEARCE, Secretary ‘ J. H. ROGERS, Inspector W. H. WOOD, Inspector J. D. PREWIT, B. S., Inspector T. C. DAVIS B. S., Inspector J. F. SCHULTZ, B. S., Inspector G. M. Morris, B. S., Inspector SUBSTATIONS: No. 1, Beeville, Bee County: R. A. HALL, B. S., Superintendent No. 2, Troup, Smith County: W. S. HOTCHKISS, Superintendent No. 3, Angleton, Brazoria County: V. E. HAFNER, B. S., Superintendent No. 4, Beaumont, Jefferson County: R. H. WYCHE, B. S., Superintendent No. 5, Temple, Bell County: A. B. CRON, B. S., Superintendent No. 6, Denton, Denton County: P. B. DUNKLE, B. S., Superintendent No. 7, Spur, Dickens County: R. E. DICKSON, B. S., Superintendent No. 8, Lubbock, Lubbock County: R. E. KARPER, B. S., Superintendent No. 9, Balmorhea, Reeves County: J. J. BAYLES, B. S., Superintendent No. 10, College Station, Brazos County: (Feeding and Breeding substation) G. R. WARREN, B. S., Animal Husband- man in Charge; Swine Husbandman R. M. SHERWOOD, B. S, Poultry Husband- man L. J. McCALL, Farm Superintendent No. 11, Nacogdoches, Nacogdoches County: G T. McNESS, Superintendent **No. 12, Chillicothe, Herdsman County: D. L. JONES, Superintendent No. 14, Sonora, Sutton-Edwards Counties: E. M. PETERS, B. S., Superintendent D. H. BENNETT, D. V. M., Veterinarian V. L. CORY, M. S., Grazing Research Botanist O. L. CARPENTER, Shepherd No. 15, Llano Grands, Hidalgo County: W. H. FRIEND, B. S., Superintendent Teachers in the School of Agriculture carrying cooperative projects on the Station: S. W. BILSING, Professor of Entomology W. L. STANGEL, Professor of Animal Hus- bandry (Hogs) R. C. WHITE, Associate Professor of Rural Sociology . P. GROUT, Professor of Dairy Husbandry _ F. A. BUECHEL, Professor of Agricultural H. V. GEIB, Assistant Professor of Economics Agronomy G. W. ADRIANCE, Associate Professor of E. O. POLLOCK, Assistant Professor of Horticulture W. E. GARNETT, Professor of Rural Sociology i-As of July 1, 1924. Agronomy *In cooperation with School of Veterinary Medicine. "In cooperation with United States Department of Agriculture. SYNOPSIS This Bulletin reports the results of a study of the weights of fleeces produced by nearly 1200 different Angora goats kept under range condi- tions on the ranch experiment station in Southwestern Texas. The first part of this Bulletin is introductory and describes the goats and the conditions under which they were kept, and defines the words which are used with a special meaning in this Bulletin. The second part of this Bulletin is concerned with the constancy of the individual fleece weights from one shearing to another. Upon this constancy _ depends the success of methods of culling for increased fleece weight. Fleece weights are found not to be as constant for Angora goats as they were for the sheep reported in Texas Bulletin No. 311. The average co- efficient of correlation between the weights of fleeces produced by the same Angora goats at different shearings was +.415i.008. The fall shearing when the goat is a year and a half old is the most reliable time for the culling of goats to increase the average fleece production of the flock. The third part of this Bulletin is concerned with the influence 0f the age of the goat upon the weight of the fleece it produces, and with the in- fluence of seasonal conditions upon the average weight of fleece produced by the flock. The female goat, like the female sheep, reaches its max- imum fleece-production in the second year of its life. Wether goats may produce still heavier fleeces at later ages. The average weight of the fleeces of mohair is more strongly influenced by changes in seasonal con- ditions than is the average weight of the fleeces of wool. Fall fleeces of mohair are heavier than spring fleeces. CONTENTS I Page Part I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Material Studied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6 Definitions . . . . . . . . . .h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l. . 7 Part II. The Influence of Individuality on Fleece Weights Previous Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9 Method of Study . ._ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9 Correlation Between the Weights of Fleeces Produced by An- gora Goats at Different Shearings (Table 1) . . . . . . . . . . . . . 14 Individuality in Different Groups of Goats . . . . . . . . . . . . . . . . . . . . . . . . 21 Statistical Significance of the Correlations (Table 2) . . . . . . . . . . . . . 22 The Influence of the Number of Individuals Involved upon the Size of the Correlation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23 Individuality in Fall Shearings Compared with Individuality in Spring Shearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 24 Correlations of Fall Shearings Compared with Correlations of Spring Shearings (Table 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 The Influence of the Length of Time Between Shearings upon the Size of the Correlation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 The Influence of the Length of Time Between Shearings upon the Size of the Correlation (Table 4) . . . . . . . . . . . . . . . . . . . . 27 The Influence of Age upon Individuality . . . . . . . . . . . . . . . . . . . . . . . .28 The Influence of Age upon the Amount of Correlation (Table 5) 30 The Influence of Season upon Individuality . . . . . . . . . . . . . . . . . . . . . . 31 The (Influence of Season upon the Amount of Correlation (Table 32 Individuality andHeredity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33 Correlations Involving Grade Does 1-51 and Grade Does 52-154 in Separate Groups and Correlations Involving All Grade Does 1-154 in One Group (Table 7) . . . . . . . . . . . . . . . . . . . 34 Part III. The Influence of Age and Season upon the Weight of Mohair Fleeces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 The Influence of Age and Season on the Weight of the Fleece (Table 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .;.....39 The Influence of Age and Season on the Weight of the Fleece (Table 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 40 The Effect of Age upon Average Fleece Weights (Table 10) . . . . . . . 48 Rainfall in Inches, Texas Agricultural Experiment Station, Substa- tion No. 14, Sonora, Texas (Table 11) . . . . . . . . . . . . . . . . . . . . . .. 50 Other Considerations in Culling Angora Goats . . . . . . . . . . . . . . . . . . . . . .. 50 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 References on Angora Goats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 54 Bulletin No. 320 March, 1924 THE INFLUENCE OF INDIVIDUALITY, AGE, AND SEASON UPON THE WEIGHTS OF FLEECES PRODUCED BY ANGORA GOATS UNDER RANGE CONDITIONS Jay L. Lush J. M. Jones PART ONE INTRODUCTION Angora goats are usually kept for one or more of three diflerent pur- poses. The first is for the mohair which they produce, the second is to keep certain kinds of brush browsed so closely as either to kill it out in a few years or at least to hold it in check, while the third is for the production of meat for human consumption. For the first purpose they have no real competitors because the mohair which they produce is a peculiar fiber well suited to certain manufacturing purposes and poorly suited to others. To a very limited extent mohair competes with wool but on the whole the two fibers are fitted for different processes of manufacture and are made into different kinds of fabrics and supplement each other instead of competing with each other. For killing brush, Angora goats come into competition with other goats, especially in the southwestern parts of the United States where many common Mexican goats are used for that purpose. In the production of meat for human food the Angora goat comes into severe competition not only with the other goats but also with sheep. At present the meat of the goat, now known officially as “chevon”, does not bring in a very large part of the total revenue derived from goats. When properly prepared it is really a very nutritious and palatable meat and deserves much Wider use as a part of the average American dietary than it has hitherto received. Thus it comes about that the Angora goat-raisers are much more de- pendent for their profits upon the quality and weight of the fleeces which they produce than the sheep-raisers are. The sheep-raiser derives a very considerable portion of his revenue from the sale of lambs and sheep for slaughter but the demand is very limited for the corresponding products of the goat-raiser and therefore the quality and weight of the fieeces which he produces are relatively more important to him. This point is well il- lustrated by the figures in the Yearbook of the United States Department of Agriculture for 1922, which show that the number of goats slaughtered annually under federal inspection from 1910 to 1922 inclusive was only about three per cent of the total number of goats in the United States at that time, while the number of sheep so slaughtered annually during the same period was more than twenty-five per cent of the entire sheep popu- lation. These facts will emphasize the importance of methods of breeding for increased mohair production and methods of handling goats so that they 6 Bulletin N0. 320 Texas Agricultural Experiment Station will produce more and better mohair, since mohair is the main source of . revenue for the goat-raiser at present. l The Angora goat is especially important to the agricultural interests of Texas because of the volume of the industry. The census of 1920 showed- that one-half of the goats of the United States were within the borders of Texas and the even greater importance of the Angora in Texas “was shown by the fact that about three-fourths of the mohair produced in the United i States in the year preceding the census was produced in Texas. The Angora i. goats in Texas are nearly all in the Edwards Plateau region of Southwestern ; Texas. , Substation No. 14 of the Texas Agricultural Experiment Station is ' located near the town of Sonora, very nearly in the center of the Edwards l Plateau, and was established primarily for the study of problems which l affect the production of goats, sheep, and cattle under range conditions. a From the very beginning of the work at this station methods of breeding ' and management which would increase the amount of mohair have been an object of study by the Experiment Station workers. This Bulletin presents an analysis of the weights recorded for individual fleeces, and presents the evidence as to how much fleece weight is influenced by the individuality and the age of the goat and how much by seasonal changes. MATERIAL STUDIED The material upon which this study is based consists of the individual weights of the fleeces shorn from the foundation registered goats at Sub- station No. 7, Spur, Texas, in the spring of 1917 and the spring of 1918, and the individual weights of all fleeces shorn from both registered and grade goats at Substation No. 14, Sonora, Texas, from the fall of 1918 to the spring of 1923. The two shearings made at Substation No. 7 were of twelve months’ growth of mohair, but after the goats were moved to Substation No. 14 shearing was done every six months in accordance with the general policy of the goat-raisers of that region. Therefore, the weights were taken at twelve different shearings consisting of two twelve-month spring shearings (1917 and 1918), and five six-month fall shearings (1918 to 1922), and five six-month spring shearings (1919 to 1923). The fall shearing of 1918 really consisted of only five months’ growth of mohair in the case of the registered does, but was of six months’ growth of mohair for the grade goats. The other nine six-month shearings varied less than ten days from an exact six months’ growth of mohair in each. Thus it will be seen that these shearings cover a period of seven years’ growth of mo- hair and therefore were subject to the possible influence of a number of extreme variations in seasonal conditions. Fleece weights were taken ac- curate to the nearest quarter of a pound but a slight psychological bias on the part of the weigher toward whole numbers was evidenced at one or two shearings by the excess of even and half pound weights over quarter and three-quarter-pound weights. Thus it is absolutely accurate to say that weights were always accurate within less than a half pound and nearly always accurate within a quarter of a pound. Factors Influencing Weights of Angora Fleeces 7 The goats were run on the range under conditions typical of that re- gion, which is to say that they were not given any feed except a little cot- tonseed cake at times when there was very little browse to be had, as in the latter part of the winters following drouthy seasons. They received no shelter except the natural shelter of the trees and brush and the protection of a shed during rainy weather immediately after shearing. The registered goats were of various ages and were purchased from several different breeders. The term, “Foundation registered does,” as used in the tables later in this Bulletin, signifies all the purchased registered does and also the registered does born at Substation No. 7 in 1917 and 1918 in the case of shearings when these were more than two years old. The grade does were purchased in three different lots from two different breeders. Grade does 1-51 and grade does 52-154 were nearly all of the same age, most of them having been born in 1916, but they were from different breeders and does 1-51 were distinctly superior to the other " group as mohair-pro- ducers, and hence their records have been considered separately. Grade does 292-416 were purchased from the same breeder as does 1-51, but were a year younger, all or nearly all of them, having been born in 1917. DEFINITIONS The weight of fleece which an Angora goat will produce is determined by many different influences but, so far as the practical breeder is con- cerned, these influences may be divided into three classes. In the first class are the permanent individual differences between the goats. In the second class are the influences which produce temporary effects and do not affect all of the goats equally. In the third class are influences which produce temporary effects but affect all of the goats equally. Individuality is used in this Bulletin to include all the influences of the first class, that is, all the permanent differences between individuals. Individuality includes all of the differences in heredity and also some per- manent differences produced by environment, such as, for instance, a severe stunting of a goat’s growth due to its having lost its mother while very young. The second class of influences includes all those which cause the fleece weights of one goat to vary at different shearings in a way in which the fleece weights of the other goats of the same age and sex, and of similar breeding do not vary. Some examples of this class of influences are pregnancy, the suckling of a kid, temporary illness. Season is used in this Bulletin to include all influences of the third class except age. Most of these influences are climatic. Examples are the amount and distribution of rainfall, temperature, humidity, and abundance or scarcity of feed. In the analysis of fleece-weight records, influences of age and sea- son can be eliminated by considering only the weights of fleeces from goats which were of the same age and sex and were sheared at the same time and had been given the same treatment since their preceding shearing. 8 Bulletin N0. 320 Texas Agricultural Experiment Station Differences found in the weight of fleece produced by two goats under such identical treatment must be due to influences of the first and sec- ond classes. It is very important to know how much of these differences is due to influences of the first class, that is, to permanent individual dif- ferences between the goats, because these differences are the raw ma- terial upon which selection can work. If the permanent individual dif- ferences in fleece Weight are numerous and large, a decided increase in the average fleece weight of the flock can be secured by careful culling. If individuality is relatively unimportant in determining fleece weight, then culling will be of little use as a means of increasing the average fleece weight of the flock, no matter how carefully it is practiced. Part II of this Bulletin gives the analysis of the importance of in- dividuality as it was actually found among the goats owned by the Ex- periment Station, and Part III gives the analysis of the effect of age and season upon the weight of fleece. - mirth", W"|VW""- TWlTPW-mvwr Factors Influencing Weights of Angora Fleeces 9 PART II THE INFLUENCE OF INDIVIDUALITY ON FLEECE WEIGHTS PREVIOUS STUDIES S0 far as the authors know, this question has not been studied else- where in any detail although general statements referring to individual differences between goats are found in various bulletins on the subject of the Angora goat and indicate that the writers of those publications appreciated from practical experience that individuality was of some considerable importance. Two detailed studies of this same question have been made on sheep and they will be referred to frequently in this Bulletin for comparison. The first one was reported in Bulletin No. 127 of the Wyoming Agricul- tural Experiment Station and concerned the weight of the scoured fleeces produced by twenty-nine Rambouillet wethers one year on the range and three years in the feed lot. The second detailed study was reported in Bulletin No. 311 of the Texas Agricultural Experiment Station and con- cerned the grease (or unscoured) weights of the fleeces produced by 12 Corriedale ewes and 492 Rambouillet sheep of different ages and sexes, each of which was sheared at least twice (some of them as many as seven times) between the spring of 1918 and the spring of 1923, at Substation No. 14. The results given in Bulletin No. 311 of the Texas Station are especially suitable for comparison with the results given in this Bulletin because the Rambouillet sheep and Angora goats were not only under the same climatic conditions and same general system of management but were actually run in the same pastures and therefore are comparable in every way except that the shearing was done at slightly different sea- sons of the year. METHOD OF STUDY The method of studying individuality was to take all the goats of the same age and sex which were sheared at two different times and rank them in the order of the weight of the fleece which they produced at the first shearing and then see how nearly they would come to ranking in the same order according to the weights of their fleeces at the second shearing. The method used in doing this is known to mathematicians as the method of correlation and the number which expresses the result is known as the “coefficient of correlation.” The coefficient of correlation is an abstract number which can never be less than minus one nor more than plus one. If the two rankings should be exactly the same, the coefficient of correlation would be plus one and we would say that the correlation was perfect. Of course in actual data that never happens because there are too many temporary causes of variation. If the two rankings had no relation to each other the coefficient of correlation would be zero, and We would say that there was no correlation and would know that the goat which sheared a heavy fleece one time was just as likely as not to shear a light fleece the next time. If the second ranking were 10 Bulletin No. 320 Texas Agricultural Experiment Station exactly opposite to the first the coefficient of correlation would be minus‘; one, and we would say that there was perfect negative correlation, and‘, ' we would know that the goat which sheared a heavy fleece one time was i certain to shear a light fleece the next time. As already stated, correlations in actual practice are never perfect r and their importance is judged by their size. For most practical pur-Ia poses (for instance, as a guide in selection), a correlation is ofwery. little importance if its coefficient is less than .30 and is of very great im- ' portance if its coefficient is greater than .60. The importance of the correlation, increases with the square of its coefficient and therefore the higher coefficients show correlations ever so much more important than I the lower ones. g '1 There were 302 different comparisons concerned in this study and of course it is impossible to show within the limits of this Bulletin every one of these correlation tables. However, three correlation tables are shown _ as samples in Figures 1 to 3. These three correlation tables were se-y v1 lected for the following reasons: Figure 1 shows the table including the largest number of individuals and is a representative table. Figure 2 shows the table which gives the highest of all correlations found and is therefore not a truly representative table. Figure 3 shows the table which gives the lowest of all correlations found and is therefore not a truly representative table. F1eece.Wb1ght, Fall of 1918. 3 eeeeseeesasgsaeesae g r0‘ e a a“; o n In i. LO a 1.00 1 1 .25 O .50 1 1 3 5 c; .75 l 2 1 4 1919; $2.00 2 3 5 "4 .25 1 1 2. 2 2 1 2 1 12 Average = 2.64- lbs. ‘*3 .50 1 1 5 5 3 3 l 1 2 1 21 .75 1 1 :5 5 5 1 1 17 Standard Deviation = E?3.00 1 1 1 1 1 3 2 3 1 1 15 .710 lbs.‘ Q .35 1 1 4 3 4 15 "1 _5O 1 1 2 4 1 9 .coeffic1ent of va§1at1ox J .75 2 z 1 1 s = 25-1 /== {$04.00 1 1 1 s "i; .25 1 1 1 4 a j .50 2 2 0 .75 0 §5.oo i1 1 i" .25 ' .50 Totals 1 04876717211514365122 117 1918- ' Coefficient of Correla- A"°"a5° = 3'45 1b“ tion = +.44s + .050 Standard Deviation = .782 lbs. - Coefficient of Variation = 22.7 % Figure 1. Grade _Angora Does, Nos. 292-416, most of them born in 1917. Corre- lation getween the weights of the fleeces shorn in the fall of 1918 and in the spring of 191 . Factors Influencing Weights of Angora Fleeces 11 Fleece Weight, Spri Q of 1921. 2 ' OKJOKSOIQOLOOLQOKDOLOOLGOLDO t6 % €§°¥9§9¥Q§Q¥9§Q¥9E9 3 2 1-1 oi n ~34 .8611.030 Fall of 1921 and Spring of 1922 . . . . . . . . . . . . ..l 34 .1951.111 l I Average of 28 correlations for grade does 155-291. . . . .2491.034 Grade does 292-416, born in 1917, purchased. (Includes a total of 120 different does which were sheared at least twice) Fall of 1918 and Spring of 1919 . . . . . . . . . . . . . . 117 .4481.050 Fall of 1919 . . . . . . . . . . . . . . . 112 .4951.048 Spring of 1920 . . . . . . . . . . . . . 69 3181.073 Fall of 1920 . . . . . . . . .. 108 .5611.045 Spring of 1921 . . . . . . . . . . .. 96 .4721.054 Fall of 1921 . . . . . . . . . . . . . . . 48 .4061.081 Spring of 1922 . . . . . . . . . . . . . 48 .3311.087 Fall of 1922 . . . . . . 12 .0011.195 Spring of 1923 . . . . . . . . . . . . . 11 .3221.182 Spring of 1919 and Fall of 1919 . . . . . . . . . . . . . . 113 .3961.054 Spring of 1920 . . . . . . . . . . . . . 71 .5641.055 Fall of 1920 . . . . . . . . . . . . . . . 109 .4561.051 Spring of 1921 . . . . . . . . . . .. 97 .6191.042 Fall of 1921 . . . . . . . . . . . . . . . 49 .2811.089 Spring of 1922 . . . . . . . . . . . . . 49 .2501.090 Fall of 1922 . . . . . . . . . . . . . . . 12 .0741.194 Spring of 1923 . . . . . . . . . . . . . 11 .0741.202 Fall of 1919 and Spring of 1920. . . . . . . . . . . . . . 69 .3501.071 Fall of 1920 . . . . . . . . .. 108 .6501.038 Spring of 1921 . . . . . . . . . . .. 95 3671.060 Fall of 1921 . . . . . . . . . . . . . . . 49 .6001.062 Spring of 1922 . . . . . . . . . . .. 48 .3011.089 Fall of 1922 . . . . . . . . . . . . . .. 12 .5591.134 Spring of 1923 . . . . . . . . . . . .. 11 .5341.145 Spring of 1920 and Fall of 1920 . . . . . . . . . . . . .. 69 .4271.066 Spring of 1921 . . . . . . . . . . . .. 60 .6591.049 Fall of 1921 . . . . . . . . . . . . . . . 33 .4181.097 Spring of 1922 . . . . . . . . . . .. 32 .1141.118 Fall of 1922 . . . . . . . . . . . . . .. 9 .5011.168 Spring of 1923 . . . . . . . . . . .. 9 .6751.122 Fall of 1920 and Spring of 1921 . . . . . . . . . . . . . . 94 .4021.058 Fall of 1921 . . . . . . . . . . . . . .. 48 .4171.081 Spring of 1922 . . . . . . . . . . . . . 46 3911.083 Fall of 1922 . . . . . . . . . . . . . . . 12 .4971.147 Spring of 1923 . . . . . . . . . . . .. 11 .5451.142 Spring of 1921 and Fall of 1921 . . . . . . . . . . . . . . 46 .3211.089 Spring of 1922 . . . . . . . . . . .. 45 .3941.085 Fall of 1922 . . . . . . . . . . . . . .. 11 .5561.141 Spring of 1923 . . . . . . . . . . . . . 10 .6851.113 Fall of 1921 and Spring of 1922 . . . . . . . . . . . . .. 46 .0831.099 16 Bulletin N0. 320 Texas Agricultural Experiment Station Table 1. Correlations between the Weights of Fleeces Produced by Angora Goat: at Different Shearings—(Continued) No. of Goats Coefficient of Included Correlation Fall of 1922 . . . . . . . . . . . . . .. 10 .4761.165 Spring of 1923 . . . . . . . . . . .. 9 .5361.160 Spring of 1922 and Fall of 1922 . . . . . . . . . . . . . . 11 .4381.164 Spring of 1923 . . . . . . . . . . . . . 10 .3941.180 Fall of 1922 and Spring of 1923 . . . . . . . . . . . . .. 11 .7161.099 Average of 45 correlations for grade does 292-416. .. . .4241.017 Grade does 418-684, born at the Station in the Spring of 1919 out of does 1-154 and 292-416. (Includes a total of 123 different does which were sheared at least twice) Fall of 1919 and Spring of 1920 . . . . . . . . . . . . . . 105 .4411.053 Fall of 1920 . . . . . . . . . . . . . .. 112 .5691.043 Spring of 1921 . . . . . . . . . . .. 101 ' .2031.064 Fall of 1921 . . . . . . . . . . . . . . . 74 .4801.060 Spring of 1922 . . . . . . . . . . . .. 76 .2861.071 Fall of 1922 . . . . . . . . . . . . . .. 41 .2201.100 Spring of 1923 . . . . . . . . . . . . 33 .2621.109 Spring of 1920 and Fall of 1920 . . . . . . . . . . . . . . 108 .5201.047 Spring 0f 1921 . . . . . . . . . . .. 96 .5721.046 Fall of 1921 . . . . . . . . . . . . . .. 73 .4001.066 Spring of 1922 . . . . . . . . . . . . ., 74 .4181.065 Fall of 1922 . . . . . . . . . . . . . . . 41 .2981.096 Spring of 1923 . . . . . . . . . . .. 33 .4701.092 Fall of 1920 and Spring of 1921 . . . . . . . . . . . . .. 104 .3731.057 Fall of 1921 . . . . . . . . . . . . . . . 78 .5611.052 Spring of 1922 . . . . . . . . . . . .. 80 .3361.067 Fall of 1922 . . . . . . . . . . . . . .. 43 .5711.069 Spring of 1923 . . . . . . . . . . .. 35 .2561.107 Spring of 1921 and Fall of 1921 . . . . . . . . . . . . . . 76 .2701.072 Spring of 1922 . . . . . . . . . . . .. 78 5641.052 Fall of 1922 . . . . . . . . . . . . . . . 43 .3821.088 Spring of 1923 . . . . . . . . . . . . . 35 .6201.070 Fall of 1921 and Spring of 1922 . . . . . . . . . . . . .. 79 .2951.069 Fall of 1922 . . . . . . . . . . . . . . . 43 6201.075 Spring of 1923 . . . . . . . . . . . . . 35 .3041.104 Spring 0f 1922 and Fall of 1922 . . . . . . . . . . . . . . 43 .2641.096 Spring of 1923 . . . . . . . . . . . .. 35 .53 1.081 Fall of 1922 and Spring of 1923 . . . . . . . . . . . . ..l 36 .34 1.099 Average of 28 correlations for grade does 418-684.. . . .4051.016 Grade does 687-941, born at the Station in the Spring of 1920 out of does 1-416. (Includes a total of 78 different does which were sheared at least twice) . Fall of 1920 and Spring of 1921 . . . . . . . . . . . . . . 73 .5181.058 Fall of 1921 . . . . . . . . . . . . . . . 65 .5621.057 Spring of 1922 . . . . . . . . . . . . . 64 .4931.064 Fall of 1922 . . . . . . . . . . . . . . . 41 .5431.074 Spring of 1923 . . . . . . . . . . . . . 35 .5501~.080 Spring of 1921 and Fall of 1921 . . . . . . . . . . . . . . 67 .5621.056 Spring of 1922 66 £321.06!) Fall of 1922 . . . . . . . . . . . . . .. 41 .5001.079 Spring of 1923 . . . . . . . . . . . . . 35 5981.073 Fall of 1921 and Spring of 1922 . . . . . . . . . . . .. 67 4811.063 Fall of 1922 . . . . . . . . . . . . . . . 43 .5381.073 Spring of 1923 . . . . . . . . . . . . . 37 .6171.069 Spring of 1922 and Fall of 1922 . . . . . . . . . . . . . . 42 .4801.080 Spring of 1923 . . . . . . . . . . .. 36 .6171.070 Fall of 1922 and Spring of 1923 . . . . . . . . . . . . .. 37 '.5401.079 Average of 15 correlations for grade does 687-941. . . 6421.007 Factors Influencing Weights of Angora, Flleeces 17 Table 1. Correlations between the Weights of Fleeces Produced by Angora Goats at Different Shearings—-(Continued) No. of Goats Coefiicient of Included ~ Correlation ____.___e l l l Grade does 943-1141, born at the Station in the Spring of 1921 out of does 1-684 Fall of 1921 and Spring of 1922 . . . . . . . . . . . . . . . . 87 .4201.060 Spring of 1923 . . . . . . . . . . .. 10 4891.163 Grade does 1142-1178, born at the Station in the Spring of 1922 out of does 1-941. Fall of 1922 and Spring of 1923 . . . . . . . . . . . . . 19 2401.146 Average of 162 correlations of eight different groups of grade does, involving shearing records of 631 different individuals . . . . . . . . . . . . . . . . . . . . . . . . . . 3921 . 011 Grade wethers 157-290, born at the station in the Spring of 1918 out of does 1-154. (Includes a total of 47 different wethers which were sheared at least twice) Fall of 1918 and Spring of 1919 . . . . . . . . . . . .. 44 .4001.085 Fall of 1919 . . . . . . . . . . . . . . . 42 .4651.082 Spring of 1920 . . . . . . . . . . .. 42 --.0741.104 Fall of 1920 . . . . . . . . . . . . . .. 35 .4731.089 Spring of 1921 . . . . . . . . . . .. 33 —-.0841.117 Spring of 1919 and Fall of 1919 . . . . . . . . . . . . .. 45 .4701.078 Spring of 1920 . . . . . . . . . . .. 45 .5421.071 Fall of 1920 . . . . . . . . . . . . . . . 37 .2551.104 Spring of 1921 . . . . . . . . . . . . . 34 .3191.104 Fall of 1919 and Spring of 1920 . . . . . . . . . . . . . . 44 ‘ 1631.095 Fall . . . . . 36 .6641.063 Spring of 1921 . . . . . . . . . . . . . 33 .4121.098 Spring of 1920 and Fall of 1920 . . . . . . . . . . . . . . 37 1581.108 Spring of 1921 . . . . . . . . . . . . . 34 .5441.082 Fall of 1920 and Spring of 1921 . . . . . . . . . . . . .. 33 .0781.117 Grade wethers 417-686, born at the station in the Spring of 1919 out of does 1-154 and 292-416 (Includes a total of 119 different wethers which were sheared at least twice) Fall of 1919 and Spring of 1920 . . . . . . . . . . . .. 114 .4361.051 Fall of 1920 . . . . . . . . . . . . . . . 106 .5851.043 Spring of 1921 . . . . . . . . . . . . 93 .1431.069 Spring of 1920 and Fall of 1920 . . . . . . . . . . . . . 106 6761.044 Spring of 1921 . . . . . . . . . . .. 94 5931.045 Fall of 1920 and Spring of 1921 . . . . . . . . . . . . .. 95 .4591.055 Grade wethers 688-942, born at the Station in the Spring of 1920 out of does 1-416. Fall of 1920 and Spring of 1921 . . . . . . . . . . .. 70 .5451.057 Grade wethers 944-1139 born at the Station in the Spring of 1921 out of does 1-684. Fall of 1921 and Spring of 1922 . . . . . . . . . . . . . . - 66 .2811.077 Grade wethers 1145-1179, born at the Station in the Spring of 1922 out of does 1-941 Fall of 1922 and Spring of 1923. . .. . . . . . . . . . 11 3431.180 Average of 24 correlations on a total of five differ- ent groups of wethers involving shearing records from 313 different individuals . . . . . . . . . . . . . . . . .1 3691.028 18 Bulletin N0. 320 Texas Agricultural Experiment Station Table 1. Correlations between the Weights of Fleeces Produced by Angora Goats at Different Shearings——-(Continued) l No. of Goats Coefficient of l Included Correlation Registered Angora Bucks, purchased or born in 1918 Long Spring of 1919 and Fall of 1919 . . . . . . . . 12 .5581.134 Reggztered bucks born at the Station in the Spring of’ 1 0 ' (Includes a total of 18 different individuals which were sheared at least twice) Fall of 1920 and Spring of 1921 . . . . . . . . . . . .. 14 -—.3301.161 Long Spring of 1922 . . . . . ..] 12 .1761.189 Spring of 1921 and Long Spring of 1922 . . . . .. 16 .3651.146 Registered bucks born at the Station in the Spring of 1921. Fall of 1921 and Spring of 1922 . . . . . . . . . . . . . 24 .6101.087 Registered bucks born at the Station in the Spring of 1922. ~ Fall of 1922 and Spring of 1923 . . . . . . . . . . . .. 13 1501.145 Average of 6 correlations on 4 different groups of reg- istered bucks involving shearing records from 67 dif- ferent individuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2551 .086 Foundation Registered Does, purchased from various sources, born in 1917 or earlier, most of them in 1915, and no shearing records used where the does were not at least eighteen months old. This also in- cludes registered does born at the station in 1917 and 1918 but no shearing records of these before they were two and one-half years old were used. (66 different does are included). Long Spring of 1917 and Long Spring of 1918.. 21 .1161.145 Fall of 1918 . . . . . . . . . . . . . . . 20 .3101.136 Spring of 1919 . . . . . . . . . . .. 20 .4691.118 Fall of 1919 . . . . . . . . . . . . . . . 19 .5151.114 Spring of 1920 . . . . . . . . . . . . . 20 2911.138 Fall of 1920 . . . . . . . . . . . . . . . 18 .3591.138 Spring of 1921 . . . . . . . . . . .. 16 ——.0251.169 Fall of 1921 . . . . . . . . . . . . . .. 16 .2821.155 Spring of 1922 . . . . . . . . . . .. 15 .2531.163 Fall of 1922 . . . . . . . . . . . . . .. 16 .2651.157 Spring of 1923 . . . . . . . . . . .. 11 .1901.196 Long Spring of 1918 and Fall of 1918 . . . . . . . . .1 20 .3981.127 Spring of 1919 . . . . . . . . . . . ..I 20 .4161.125 Fall of 1919 . . . . . . . . . . . . . .. 19 .3361.137 Spring of 1920 . . . . . . . . . . . . . 20 .4391.122 Fall of 1920 . . . . . . . . . . . . . . . 18 .3371.141 Spring of 1921 . . . . . . . . . . . . . 16 .3251.151 Fall of 1921 . . . . . . . . . . . . . .. 16 .5141.124 Spring of 1922 . . . . . . . . . . . . . 15 .5821.115 Fall of 1922 . . . . . . . . . . . . .. 16 .4331.137 Spring of 1923 . . . . . . . . . . .. 11 .4171.168 Fall of 1918 and Spring of 1919 . . . . . . . . . . . . .. 52 .4441.075 Fall of 1919 . . . . . . . . . . . . . .. 48 .3011.089 Spring of 1920 . . . . . . . . . . . . . 51 3441.083 Fall of 1920 . . . . . . . . . . . . . . . 48 .3081.088 Spring of 1921 . . . . . . . . . . . .. 46 2431.094 Fall of 1921 . . . . . . . . . . . . . .. 44 .3661.088 Spring of 1922 . . . . . . . . . . . . . 43 .5621.070 Fall of 1922 . . . . . . . . . . . . . . . 45 .3231.090 Spring of 1923 .. 34 ‘.1831.112 Spring of 1919 and Fall of 1919 . . . . . . . . . . . . . . 50 .5061.071 Spring of 1920 . . . . . . . . . . .. 54 .6651.051 Fall of 1920 . . . . . . . . . . . . . . . 51 .5051.070 Spring of 1921 . . . . . . . . . . .. 48 , .5171.0'71 Factors Influencing Weights of Angora Fleeces 19 Table 1. Correlations between the Weights of Fleeces Produced by Angora Goats at Different Shearings—-(Continued) No. of Goats Coefficient of Included Correlation a I - I Fall of 1921 46 .3271.089 Spring of 1922 . . . . . . . . . . . . . 45 .5371.072 Fall of 1922 . . . . . . . . . . . . . . . 47 .5061.073 Spring of 1923 . . . . . . . . . . . . . 36 .5061.084 Fall of 1919 and Spring of 1920 . . . . . . . . . . . . 49 .3891.082 Fall of 1920 . . . . . . . . . . . . . .. 47 .5601.068 Spring of 1921 . . . . . . . . . . . .. 44 .4821.078 Fall of 1921 . . . . . . . . . . . . . . . 42 .4091.087 Spring of 1922 . . . . . . . . . . . . . 41 .4551.084 Fall of 1922 . . . . . . . . . . . . . . . 43 .5801.068 Spring of 1923 . . . . . . . . . . . .. 34 .5061.086 Spring of 1920 and Fall of 1920 . . . . . . . . . . . . . . 5O .5331.068 Spring of 1921 . . . . . . . . . . .. 47 .4781.076 Fall of 1921 . . . . . . . . . . . . . . . 45 .4341.082 Spring of 1922 . . . . . . . . . . .. 44 .5781.068 Fall of 1922 . . . . . . . . . . . . . . . 46 .5401.070 Spring of 1923 . . . . . . . . . . .. 36 .4121.093 Fall of 1920 and Spring of 1921 . . . . . . . . . . . . . . 58 .5581.061 Fall of 1921 . . . . . . . . . . . . . . . 54 .5111.068 Spring of 1922 . . . . . . . . . . .. 54 .4181.076 Fall of 1922 . . . . . . . . . . . . . .. 53 .7I41.045 Spring of 1923 . . . . . . . . . . . .. 41 .4841.081 Spring of 1921 and Fall of 1921 . . . . . . . . . . . . ..| 54 .563i.063 Spring of 1922 . . . . . . . . . . . . .1 54 .5431.065 Fall of 1922 . . . . . . . . . . . . . ..| 53 .4011.078 Spring of 1923 . . . . . . . . . . . . .| 41 .6601.060 Fall of 1921 and Spring of 1922 . . . . . . . . . . . . ..| 53 .2261.088 Fall of 1922 . . . . . . . . . . . . . . . 52 .377+ 080 Spring of 1923 . . . . . . . . . . . .. 40 .5101.079 Spring of 1922 and Fall of 1922 . . . . . . . . . . . . ..| 51 .4781 073 Spring of 1923 . . . . . . . . . . . . . 39 .5341.077 Fall of 1922 and Spring of 1923 . . . . . . . . . . . . .. 41 .6181.065 Average of 66 correlations for the foundation reg- istered does . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4291.011 Registered does 50-93, born at the Station in the Spring of 1919 (Includes a total of 28 different individuals) Fall of 1919 and Spring of 1920 . . . . . . . . . . . . 20 .4901.115 Fall of 1920 . . . . . . . . . . . . . .. 2O .4601.119 Spring of 1921 . . . . . . . . . . . . 20 .3201.135 Fall of 1921 . . . . . . . . . . . . . . . 19 .5341.111 Spring of 1922 22 2451 135 Fall of 1922 . . . . . . . . . . . . . .. 20 .0611.150 Spring of 1923 . . . . . . . . . . .. 19 .3711.133 Spring of 1920 and Fall of 1920 . . . . . . . . . . . .. 18 .7791.063 Spring of 1921 . . . . . . . . . . . .. 20 .6631.085 Fall of 1921 . . . . . . . . . . . . . .. 19 .2911.142 Spring of 1922 . . . . . . . . . . . .. 21 3821.126 Fall of 1922 . . . . . . . . . . . . . .. 19 3761.133 Spring of 1923 . . . . . . . . . . . .. 18 .5021.119 Fall of 1920 and Spring of 1921 . . . . . . . . . . . . .. 21 .7071.074 Fall of 1921 . . . . . . . . . . . . . .. 20 .7381.069 Spring of 1922 . . . . . . . . . . . .. 22 .6211.089 Fall of 1922 . . . . . . . . . . . . . .. 20 .7641.063 Spring of 1923 . . . . . . . . . . . . . 19 .6951.080 Spring of 1921 and Fall of 1921 . . . . . . . . . . . . ..| 23 .5291.101 Spring of 1922 . . . . . . . . . . .. 24 .7001.070 Fall of 1922 . . . . . . . . . . . . . .. 22 4601 113 Spring of 1923 . . . . . . . . . . . .. 21 .5911 096 Fall of 1921 and Spring of 1922 . . . . . . . . . . . . . .| 24 .5301.099 Fall of 1922 . . . . . . . . . . . . . .. 22 .4831.110 \ Spring of 1923 . . . . . . . . . . .. 21 .6641 082 Spring of 1922 and Fall of 1922 . . . . . . . . . . . . .. 25 6061.085 2O Table 1. Different Shearings—- ( Continued) Bulletin N0. 320 Texas Agricultural Experiment Station Correlations between the Weights of Fleeces Produced by Angora Goats at No. of Goats Coefficient of l Included Correlation 4 Spring of 1923 . . . . . . . . . . . . 24 .631i.083 Fall of 1922 and Spring of 1923 . . . . . . . . . . . . .. 24 .648i.080 Average of 28 correlations for the registered does born in 1919 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .530i.022 Registered does 103-150, born at the station in the Spring of 1920. (Includes a total of 15 individuals) Spring of 1921 and Fall of 1921 . . . . . . . . . . . . . . 11 136211.114 Spring of 1922 . . . . . . . . . . . .. 10 .318:.192 Fall 0f 1922 . . . . _ . . . . . . . . .. 10 .026i-.213 "Fall of 1921 and Spring of 1922 . . . . . . . . . . . . .. 11 .289i.186 Fall 0f 1922 . . . . . . . . . . . . . . . 11 .415i.169 Spring of 1923 . . . . . . . . . . . . . 10 .5731 . 143 Spring of 1922 and Fall of 1922 . . . . . . . . . . . . . . 14 .775i.072 Spring of 1923 . . . . . . . . . . . . 13 1361.086 Fall of 1922 and Spring of 1923. . . . . . . . . . . . . . 13 .796i.069 Average of 9 correlations for the registered does born in 1920 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 510+ 056 Registered does 154-225, born at the Station in the Spring of 1921. (Includes a total of 30 individuals) Fall of 1921 and Spring of 1922 . . . . . . . . . . . . . . 30 .305i.112 Fall of 1922 27 .4251-.106 _ Spring of 1923 . 26 5151.097 Spring of 1922 and Fall of 1922 . . . . . . . . . . . . .. 27 .614i.080 Spring of 1923 . . . . . _ . . . . . .. 26 .592-_+-.086 Fall of 1922 and Spring of 1923. . . . . . . . . . . . . . 24 .802i.049 Average of 6 correlations for the registered does born‘ in 192 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5421.043 Registered Does 227-282, born at the Station in the Spring of 1922. Fall of 1922 and Spring of 1923 . . . . . . . . . . . .. 16 3491.148 Average of the 110 correlations on five groups of reg-I istered does including 155 different individuals .467i.011 Summary of Table 1 l j Percentage of Average Individual Dif- Number of ferent Goats In-,' Coefficient of ferences Which I gNumber of Dif-{ l i Correlations l volved } Correlation Are Permanent ‘ . \ f l Grade Does 162 631 1 3921.011 15.4% Grade Wethers. . ., 24 3 31s ; .3s9:.o2s 13.6% ‘ ‘ \ Registered Bucks 6 67 “ .255i.068 6.5% Registered Does. .1 110 j 155 .467i.011 21.8% I 1 l f All Goats 302 ‘I 1166 .415i.008 17.2% i 4 Factors Influencing Weights of Angora Fleeces 21 VARIATIONS IN INDIVIDUALITY IN DIFFERENT GROUPS The differences between the average coefficients of correlation for the different groups of goats shown in the summary of Table 1 are as follows: l Difference DDilgclelzldnbz kiw _ H W _ 1__W_7 Probable Error Grade Does and Grade Wethers . . . . . . . . . . . . . . . . . .0231.030 .8 Grade Does and Registered Bucks . . . . . . . . . . . . . . .1371.087 1.6 Grade Does and Registered Does . . . . . . . . . . . . . . . . . .0751.016 4.7 Grade Wethers and Registered Bucks . . . . . . . . . . . . .1141.090 1.3 Grade Wethers and Registered Does . . . . . . . . . . . . . . ..0981.030 3.3 Registered Bucks and Registered Does . . . . . . . . . . . .2121.08‘7 2.4 The only statistically significant difference is that between the aver- age correlation for the grade does and the average correlation for the registered does, which (although small) is 4.7 times as large as its prob-P able error. The difference between the average correlation for the grade wethers and the average correlation for the registered does is on the border line of significance, being 3.3 times as large as its probable error. The possibility that both of these differences should be as large as they are and both in the same direction just as a matter of chance is so remote that we can safely conclude that there is a real reason why the registered does showed a higher correlation than the grade does and grade wethers. Various conjectures can be made as to what that reason is, but the one which fits the facts best and seems truest to the authors is that there was more genetic variability among the registered does which were ob- tained from several different sources and which were, for experimental reasons, mated to various types of bucks, than among the grade does of which thefoundation stock all came from two flocks (most of it from one) and which were bred to registered bucks of a rather uniform general type for the production of the grade goats born at the station. Too much importance should not be attached to the differences be- tween the average coefficients of correlation shown in the summary of Table I because the groups averaged together in that summary werekcom- posed of smaller groups which did not all show the same amount of cor- relation. For example, the average coefficients of correlation* for the first six groups of grade does (which are included in one group in the summary of Table I) are as follows: Does 1- 51 .3111.036 ” 52-154 5441.019 ” 155-291 2491.034 ” 292-416 .4241.017 ” 418-684 .4051.016 " 687-941 .5421.007 *Copied from Table 1. 22 Bulletin N o. 320 Texas Agricultural Experiment Station The differences between the average coefficients of correlation for these different groups of grade does are as follows: Difference Difference Divided by Probable Error Does 1- 51 and does 52-154 . . . . . . . . . . . . . . . . . . .2331.041 ~ 5,7 ” ” ” does 155-291 . . . . . . . . . . . . . . . . . . .0621.050 1.2 " ” ” does 292-416 . . . . . . . . . . . . . . . . . . .1131.040 2.8 " ” ” does 418-684 . . . . . . . . . . . . . . . . . . .0941.039 2.4 " ” ” does 687-941 . . . . . . . . . . . . . . . . . . .2311.037 6.2 Does 52-154 and does 155-291 . . . . . . . . . . . . . . . . . . 3051.039 7.8 ” ” ” does 292-416 . . . . . . . . . . . . . . . . . . .1201.025 4.8 " ” " does 418-684 . . . . . . . . . . . . . . . . . . .1391.025 5.6 ” " ” does 687-941 . . . . . . . . . . . . . . . . . . .0021.020 i .1 Does 155-291 and does 292-416 . . . . . . . . . . . . . . . . . . .1751.038 ‘ 4.6 ” ” " does 418-684 . . . . . . . . . . . . . . . . . . .1561.038 4.1 ” ” ” does 687-941 . . . . . . . . . . . . . . . . . . 2931.035 8.4 Does 292-416 and does 418-684 . . . . . . . . . . . . . . . . . . .0191.023 .8 ” " " does 687-941 . . . . . . . . . . . . . . . . . . .1181.018 1 6.6 Does 418-684 and does 687-941 . . . . . . . . . . . . . . . . .. .1371.017 ‘~ 8.1 It will be seen that each of these six groups of does shows an average coefiicient of correlation significantly different from that of sev- eral of the other five groups. Some of the reasons for these differences are definitely known. Thus the low average correlation of does 1-51 is largely due to the fact that they were carefully selected when they were purchased and therefore did not show the full range of variation which the entire flock from which they were chosen would have shown. Does 52-154 and does 292-416 were also purchased but were not selected one by one after a careful examination as does 1-51 were. Therefore, does 52-154 and does 292-416 may naturally have been expected to show more vari- ation in permanent differences and higher correlations than does 1-51. No satisfactory explanation of the low average correlation for does 155- 291 is apparent. Neither is there any apparent explanation of the re- markable uniformity shown by does 687-941 in the size of the various co- efficients of correlation which go to make up their average coefficient of correlation. It is this uniformity which is responsible for the extreme smallness of the probable error for the average coefficient of correlation for this group. Thus it is clear that there are real differences between different groups of goats in regard to the amount of correlation which they show, al- though the reasons for those differences are not completely known. It is important to know the amount of correlation which any group of goats would show between fleece weights at different shearings because the suc- cess of culling depends on that. It is evident that the Experiment Station would have gained much more by culling does 52-154 or does 687-941 than it would by culling does 1-51 or 155-291. Further references to these differences between groups will be made later in the discussion of indi- viduality and heredity. STATISTICAL SIGNIFICANCE OF THE CORRELATIONS It will be noticed that a few of the correlations in Table 1 are neg- ative and that nearly a third of them are not large enough to be statis- Factors Influencing Weights of Angora Fleeces 23 tically significant; that is, are less than three times their probable errors. None of the negative correlations are statistically significant, and the great majority of all correlations are positive, nearly half of them being more than five times as large as their probable errors. Hence it can- not be doubted that on the average there is a significant positive corre- lation between the Weights of individual fleeces of Angora goats at dif- ferent shearings, but this correlation is not as large as the similar corre- lation for Rambouillet sheep. The correlations are summed up as to their significance in Table 2. Negative Positive Less than their probable errors . . . . . . . . . . . . . . . . . . . . . . . . . 9 , 19 From one to three times as large as their probable errors. . 5 ‘ 56 From three to five times as large as their probable errors. . 0 p 66 More than five times as large as their probable errors. . . . . 0 ‘ 148 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 i 288 Largest negative correlation (21 individuals) is —-—.346i.130 Largest positive correlation (34 individuals) is +.861i.030 THE INFLUENCE OF THE NUMBER OF INDIVIDUALS INVOLVED UPON THE SIZE OF THE CORRELATION Some of the correlations are based upon very small numbers of indi- viduals and it might be supposed that it is these correlations which have the unusually high and the unusually low coefficients or it might be sup- Number of Goats in Each Correlation Table ~52: bmkNbNbNbNfiNbNkNbOn-lv-QH NHNNnD-.1o a 211 4 O -.O9to-.0O112 21 7 ~a+.O0to+.O93 2312 111 14 a +.1O to M19213 13 1 1 12 g+.20to-r.29134 164521 2 21 1 s1 3 +.50to+.3945101-26 v9 2 1 1 1 1 4e a+\40to+.496175177643 21s 2 s 122 as '3+.50to+.59834511051144232131 2 2s 74 g+.60to+-693157162 211 1 1 s1 o +.7o to +.v91s's2 1 12 fi'+-.so to +.e9 1 11 s .,_ . Z 2911452s114s192s2114vssss 8146s s02 l3 t‘) Coefficient of Correlation = +.O97 i .038 Figure 4. The Relation between the size of the coefficient of correlation and the number of individuals upon which that correlation is based. posed that these correlations based upon very.small numbers undulyin- fluence the average value of all correlations. The relation between the number of individuals involved and the size 24 Bulletin N0. 320 Texas Agricultural Experiment Station of the coefficient of correlationis shown in Figure 4, which is itself in the form of a correlation table. The use of the correlation coefficient is not justified in this case because neither distribution is in agreement with the normal frequency curve. and regression is clearly non-linear. The cor- relation ratios (which are used instead of the coefficient of correlation in the cases of non-linear regression) are .217 and .306 for the data in Figure 4. They show that the extreme coefficients do come from the correlations involving smaller numbers of individuals and that there is a slight tendency for the correlations involving larger numbers to have larger coefficients. This table makes it seem still more probable that coefficients less than +.20 or more than +.69 are so abnormal in size merely because they are based upon insufficient numbers. ' INDIVIDUALITY IN FALL SHEARINGS COMPARED WITH INDIVIDUALITY IN SPRING SHEARINGS ~- While working over the shearing records the authors were impressed, merely by inspection, with the fact that there were many goats, partic- ularly among the wethers, which consistently produced fleeces in the fall very much heavier than the average of their group but produced fleeces of ordinary or inferior weight in the spring. There were others which did exactly the opposite; that is, produced heavy fleeces in the spring and light ones in the fall, but these were not so conspicuous. Table 3 shows that this general impression gained from glancing at the individual fleece weight records was founded on actual fact. Table 3 shows that fall shearings are correlated with other fall shearings and spring shearings are correlated with other spring shearings more closely than fall shear- ings are correlated with spring shearings. This is all the more surprising because consecutive shearings might have been expected to have been more closely correlated than shearings which were separated by at least of1e other shearing. This was actually found to be true in the case of the sheep studied in Texas Bulletin 311, and is to be expected for the reason that there will be temporary environmental influences, such as a minor illness or parasitism, which will affect individual goats over a large part of two consecutive fleece-growing periods but will not last all through the life-times of those goats. However, in Table 3 all the correlations of consecutive shearings (except one involving registered bucks and one in- volving the foundation registered does) are correlations of fall shearings with spring shearings, and therefore we would have expected the aver- age of the “fall with spring” correlations to be higher than the others, whereas it is actually lower and the difference is statistically significant. A detailed examination of Table 3 will show that this difference is due entirely to the grade Wethers and grade doles, and shows up in every complete comparison of those groups except that the difference is small in the case of grade does Nos. 687-941. Expressed in the language of the practical breeder, all of this merely means that in the groups of grade goats there were many individuals which usually produced heavy fleeces in the fall and fleeces of ordinary Factors Influencing Weights of Angora Fleeces 25 weight in the spring and many other individuals which usually produced heavy fleeces in the spring and fleeces of ordinary weight in the fall. At present we can do no more than speculate as to the reasons for this habit. It is quite possible that it is related to the variations in the shrinkage of individual fleeces. The fall fleeces (where this difference showed up most pronounced) were grown during the long hot summers and it may be that certain individuals responded to this hot weather by producing much more sweat and yolk in their fleeces than others. Or the difference may have been due to individual feeding habits and peculiarities of taste since the food eaten during the spring and summer naturally differed from that eaten during the fall and winter. ~ The fact that the difference was present in the grades but not in the purebreds is some indication that it rests ‘upon a hereditary basis and that by careful selection and breeding it might be possible to establish strains of’ Angora goats in which this difference would be even more pronounced than it was in the grade Angora goats on which this study was based. There does not appear to be any economic reason for attempting to estab- lish such a strain of goats, however, and since the available data are not enough to show conclusively which explanation is correct we shall have to be content with merely stating the observed fact that fall fleeces from the same goats tend to resemble each other in weight, and spring fleeces from the same goats tend to resemble each other in weight, more closely than fall fleeces and spring fleeces from the same goats tend to resemble each other in weight. Since this is true and the fall fleece is heavier than the spring fieece (as will be shown later), it would seem that the fall shear- ing is a better time to cull goats for increased mohair-production than the spring shearing. r" Table 3. Correlations of Fall Shearings Compared With Correlations of Spring Shearings ’ Shearings Correlated , . G°ats mduded Fall with 1 Fall with ; Spring with Fall l Spring Spring Average of all .440—_l_-.018 l 3771.010 j .492i.016 . .__-_.______*-._m- . _ W. . . " ._, , m ___ _ ,, , _, __ Grade does 1-51 . . . . . . . . . . . . . . .‘ . . . . . . . . . . . .233 l .238 .583 Grade does 52-154 . . . . . . . . . . . . . . . . . . . . . . . .593 .470 ‘ .717 Grade does 155-291 . . . . . . . . . . . . . . . . . . . . . .. .288 l .168 ' .424 Grade does 292-416 . . . . . . . . . . . . . . . . . . . . . . . .466 .399 '. .443 Grade does 418-684 . . . . . . . . . . . . . . . . . . . . . .. .487 327 ‘ .530 Grade does 687-941 . . . . . . . . . . . . . . . . . . . . . .. .548 .527 , .582 Grade does 943-1141 . . . . . . . . . . . . . . . . . . . .. . ] .455 i Grade does 1142-1178 . . . . . . . . . . . . . . . . . . . .. ' i .240 = Grade wethers 157-290 . . . . . . . . . . . . . . . . . . . . .534 § .209 .468 Grade wethers 417-686 . . . . . . . . . . . . . . . . . . . . .585 3 .404 .593 Grade wethers 688-942 . . . . . . . . . . . . . . . . . . . . - .545 k Grade wethers 944-1139 . . . . . . . . . . . . . . . . . .. l .281 Grade wethers 1145-1179 . . . . . . . . . . . . . . . . . . .343 ! Registered bucks . . . . . . . . . . . . . . . . . . . . . . . . .233 l .365 Foundation registered does . . . . . . . . . . . . . . . . . .445 .428 .424 Registered does 50-93 . . . . . . . . . . . . . . . . . . . . . .507 .521 l .578. Registered does 103-150 . . . . . . . . . . . . . . . . . .. .415 ‘ .520 | .527 Registered does 154-225 . . . . . . . . . . . . . . . . . .. .425 Q ' .559 .592 Registered does 227-282 . . . . . . . . . . . . . . . . . .. ‘I. .349 Number of tables involved . . . . . . . . . . . . . . . . . 56 ‘ 177 69 26 Bulletin N0. 320 Texas Agricultural Experiment Station THE INFLUENCE OF THE LENGTH OF TIME BETWEEN SHEAR- INGS UPON THE‘ SIZE OF THE CORRELATION It was shown in Texas Bulletin No. 311 that the correlation between the individual fleece weights of sheep was significantly higher in the case of consecutive shearings than in the case of shearings which were not con- secutive and that there seemed to be a tendency for the correlations to be still lower as the interval of time between the shearings was increased. It is very easy to understand why this should be so, because there are many cases of minor illness or of parasitism which extend over more than one fleece-growing period and which may therefore affect the weight of two consecutive fleeces but may not affect the weight of a fleece pro- duced three or four years later. Also it is possible that some individuals become broken-mouthed and show the effects of old age before others. This would tend to make the correlations lower between fleeces produced when the animals were old and fleeces produced when they were young than similar correlations between fleeces both of which were produced when the animals were young or both of which were produced when the animals were old. It was to show whether this same state of afiairs ex- isted among Angora goats that Table 4 was prepared. At first glance Table 4 does not seem to conform to expectation at all since the correlations for consecutive shearings are significantly lower than for shearings separated by one other shearing and shearings separ- ated by three other shearings. However, if Table 4 is considered in con- nection with Table 3 it becomes evident that the situation in Angora goats is really very similar to what it is in sheep. In the case of the Angora goats all of the correlations between consecutive shearings are correla- tions between fall shearings and spring shearings (except for two excep- tional cases among the registered goats), while correlations between shear- ings separated by one other shearing are all (with one exception) correla- tions between two fall shearings or between two spring shearings. To eliminate this influence of the lower correlations between spring and fall shearings, only shearings separated by an even number of shearings ought to be compared with each other and shearings separated by an odd number of shearings ought to be compared with each other. Thus correlations of consecutive shearings ought to be compared with correlations of shear- ings separated by two, four, six, eight, or ten, other shearings. Likewise correlations of shearings separated by one other shearing ought to be ‘compared with correlations of shearings separated by three, five, seven, -or nine other shearings. When this is done it will be seen that there is ra gradual decline in the value of the correlation as the length of time between the two shearings increases. Table 4 furnishes strong confirma- tion of the fact shown in Table 3, namely, that fall fleece weights resemble other fall fleece weights and springyfieece weights resemble other spring fleece weights more closely than fall fleece weights resemble spring fleece weights. Quin m. J45 T-mcnann o» $3 wan»; 0* A43» wmflanmn mrnwmamw Cue: $3 w? om 25 Ooqqlwaon m" >53»? 0* w: xfiouwbfm QCHAVQ afiwfigz“ éfhbwo Efwbww .w._.ww..8~ Ewweww mfiwTcmw mwmwbfi wt :6 O22? .52 wlfi. . . . . . . .. pg .3,“ .8“. a8 1.8% Q: 1.3m .. . .. . 03% menu 312.»: . .. . .. 1$w .23 k5 aw». 15m . . . . . . . GS?" .52 Gmlmfi. . . p3 .23 s3 2w s8 Q?» 1.2» . . . . 63in monw wwwlfim. . . . . a8 a8 é“. 2w 1E0 5w a5 5% umm . . . . . . .. m3? m8» Ewiam» . . . . . . . a3 a3 awm 6mm nwo. a3 m3 . . . . 0;? monm wwqlmxp. . . .. .. 13m 5% a3 6.: a8 . . . . . . .. . . Onwmn .83 @3152. . . . .. . . 15o ... . .. . . . . . 03% .82. Cfilfiqw. . . . . Q8 . .. . . .. . . . .. .. . . . . .. 63m." $8232 Gfilmwo. . .. M?» .3» . Em a8 lbw» . . . . . . . . . . Damn énnwnqm ‘wilfia. . .. k6 5% kw ... . . .... . . Owwmnfinfirnqmmmwllomwll a3 . .. | .. . .. . 625a 50253 wfilfiww... Q2 . . . . 03% s35: HKQIEMV . EM. . . . . . . I I .. Wowrfinnom vcnf? . . . . . . . . . ha: p3 . . I | . . Wocmmwmo: qmwwwfinnnm .82. 15a 15¢ 1am. aim umw 1&0 | 5w | 5w Q8 at .50 Wnwmmrlnm .52 2T3. . . . . a6 2w >2 5mm .$@ Qwm | hi | l. . . . | . Wowmmgfinm Q02 SwIQP» . .93. >8 m8 . ll . . . I1 . . Wnmwmwnnom moon H$|wmm. . . Gfl» 6G0 a5 . . . . . . Wnmrfinhna n02 wfilmww. . . .98 . . . . . . . . . . . .1 252?: o». nofiinmo: 3Z3 I || m=nr&2_................ ww m». 3 wm MQ 5 E a k w w 28 Bulletin N0. 320 Texas Agricultural Experiment Station THE INFLUENCE OF AGE UPON INDIVIDUALITY For economic reasons it is best to cull a flock when the animals are as young as possible, provided it is possible to do the culling as accurately at that age as at any other age. Hence it becomes important to know - whether the differences in individuality are fully developed by the time the goats are sheared as kids, or whether it will be necessary to wait until they are yearlings, two-year-olds, or even older before they can be culled on the basis of fleece weights with the greatest accuracy. Table 5 was pre- pared to show the evidence on this point. In it the correlations are sorted out according to the age of the goats involved and all those involving the same age are averaged together. Since each correlation concerns two dif- ferent ages of the same goats, each correlation is counted twice, and only twice, in this table. Two groups of does are omitted from this table be- cause they were not absolutely uniform in age and two others are shown but not included in the averages because they were not born at the Station . and therefore may not have been subject to similar environmental in- fluences while young. p It is evident from Table 5 that, with two exceptions, the correlations at different ages are very nearly the same. The fleece weights when the goats were kids (that is, were about six months old) seem to be less re- liable than the other fleece weights and the fleece weights in the fall of the yearling year (that is, when the goats were about eighteen months old) seem to. be more reliable than other fleece weights as indicators of the future weight of fleece which the goats will produce. ' _, The difference between the correlation for the kid shearing and the next lowest correlation is only one and one-half times its probable error f ut the differences between the correlation for the kid shearing and most of the other correlations are more than three times as large as their gbrobable errors and therefore we can be reasonably sure that the kid . fleece is not as accurate an indicator of the future mohair-producing ability of the goat as the later fleeces are and, other things being equal, it would be best to postpone culling until a later shearing time. The kid fleece is not as accurate an indicator as the others because of two rea- sons. In thefirst place all the kids are not born on the same day or even i-irthe same week and therefore they come to their first shearing carry- ing fleeces which have not all had the same length of time in which to grow. In the second place, there is probably more variation in the amount of milk which they get from their mothers than there is in the amount of feed which they collect for themselves at later periods in their dives. That is, the food supply for the individual kids is probably less uniform-than it is for older goats. The difference between the correlation for the fall yearling shearing and the next highest correlation is only about twice as large as its probable error but most of the differences between the fall yearling correlation and the other correlations are nearly or quite three times as large as their probable errors and therefore we can be reasonably sure that, as a rule, the fall yearling fleece weights are more reliable than the fleece weights at Factors Influencing Weights of Angora Fleeces 29 any other age as indicators of the amounts of mohair which the goats are apt to produce in the future. It is perhaps significant that this most reliable age is also the age at which the heaviest fleece is produced (as will be shown later). It would seem that differences in individuality show up best when production is best and that the conditions which tend to make the average production 10w, hurt the good-producers proportionately more than they do the poor-producers. In other words, unfavorable conditions tend to hold all the goats down to a dead level of low production. There was some indication of this also in the case of sheep as reported in Texas Bulletin 811. However, in neither case is the evidence perfectly clear- cut and free from contradictions. On the basis of the facts just shown, it is obvious that the best time to cull Angora goats for increased mohair production is at the fall shear- ing of their yearling year. If, for reasons of prices or ranch manage- ment, it is not expedient to do the culling at this age, any other age will do about as well except that they should not be culled in the fall as kids if the culling can possibly be done at any other age. m3. 3v. 08. mam. $1 m3. $0.. N20. Sm. N5. . . . . . . . . . . . . A3m-u>~ E @2505 uocv avlmmu 30w uwEO 2:. ma. E1 8N. 03. x2. 0mm. 3m. ... .. . . . ... . . . . Avwfiuiw E B1205 005 Hmulfi 30w owfifl . . .. . . . .. . .. . I . . .. mvm. mwm. Zlmwmlnmm 30w wfifimmwvm . .. ... . . . . . . . . . . . . . .. . . one. 3w. won. 2w. ... .mmN.|¢mA 30w wuhzfimom . . . . .. . . . . . . . . . . mo». mom. 0mm. mww. mmm. . . . . . . . dmfinlwofi 30w wfififimvm . . . . . . . . . . . . . 8m. 3+. 1%. m8. 8m. ma. wfi. t3. . . . amlcm 30w “Efimavm .. . .. .. . . .. Hum. . .. m2. ma. ............w~_u=nwfififiwofi . . .. . . .. .. . mwm. mwm. ...m~.:l.mw:m._2i030w.EO . .. . .. . .. . .. . . . 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Kmwwpwwmawwv 0 Xm w Xv w Xm w xm N RH H X wmfit» 7S HO< coifiuhou m0 ~0:0E< B? 000D uw< *0 00035.; Si. wuwfiufi 300G m 03w F Factors Influencing Weights of Angora Fleeces 31 THE INFLUENCE OF SEASON UPON INDIVIDUALITY It is perfectly possible that seasonal influences such as the scarcity or abundance of feed, the temperature and humidity of the air, etc., might influence the grease weights of the fleeces so much that the fleece weights of some particular season would be very much more reliable indicators of the future mohair-producing ability of the goats than the fleece weights of other seasons. Table 6 was prepared to show whether this was actually true. Since each correlation table necessarily involves shearings at two different seasons, each correlation_is counted twice and only twice in this table. The four groups of purchased does are given but are not included in the averages because of the possibility of their having been reared under quite different environmental conditions. Only two of the averages given in that table diifer significantly from the general average of all corre- lations. One of these is the average for the fall of 1918, which was very significantly lower than the general average, but which rested solely upon the kid shearings of the does and wethers which were born in 1918, dur- ing which year there was a severe drouth. The correlations for the pur- chased does are also slightly lower in the fall of 1918 than their general average but the difference is not nearly as extreme as it is in the case of the two groups which were included in the average. The average corre- lation for the spring shearing of 1923 is distinctly higher than the average of all correlations and this is found so generally among the diiferent groups that it seems unlikely that it is entirely accidental. The spring shearing of 1923 was heavier than the average spring shearing (as will be shown later) and followed six months of weather and pasture condi- tions almost ideal for goats. Since pasture conditions preceding the 1923 spring shearing were better than the average and pasture conditions preceding the 1918 fall shearing were more unfavorable than the average, this may be regarded as some further evidence that good conditions and heavy fleeces are accompanied by high correlations. However, the evi- dence does not agree completely with this hypothesis, for the 1921 fall shearing and the 1922 spring shearing, both of which were small and both of which followed periods of scanty pasture, nevertheless had average correlations which were higher than the average of all correlations. For the present we can only draw the tentative conculsion that sea- sonal variations have little or no influence upon the size of the correla- tion. One season is as good as another for culling goats for increased mohair-production. There is some evidence that the correlation is highest when it concerns seasons when the fleece weights are heaviest but this evidence is not absolutely conclusive. We have not found a perfect ex- planation for the very low correlations involving the 1918 fall shearing and for the high correlations involving the 1923 spring shearing . .8? to. 3%. wfi. $1 com. mom. m? 3%. NQ. NS. . . . . . . 30993.3» E ~05 Ewlfia 8% 02:0 a8. $3.. :5. 2a.. Sm. mwm. $3. Q8. ...........Auw~.6>u E ~05 wfilwm wuow ~25 3Q. H 3m. 2:. 5:. w? 2m. Q3. m: . 0mm. 3m. .. Qvwfiuiw E @032; ~05 Hmlfi wuow owsmv :0. Homw. wfiw m5“. o3. 3w. 3w. 5.. m? wfiw 5w. 3.»: Sm. EN. . . . . . . . .......®w~.5>~ . E wowflufi ~05 moow . wuhfiwmwuh aomfiwwcsoh m3 . H 2.». 3w. 2a. . . . mwm|bmm 8% waxzwum m3. Hmwm. 3w. 3w. 3m. m3. . . . . . mmwlvfi 8% wusfiwom $0. HOE... mo». mom. omm. 2.. 3m. . Qfilmi 3% wnzuxzmum “mo. H 0mm. 8m. 3a.. 3m. £9 , 5m. ma. m3. v.3. . . amlom $2. wfiszmom $8. Hmmm. o2. o2. ma. 2w. 2Q. »>o.| m3. . .. ..... . .235 Eséwom 9:. Hmwm mi“. m3 . . . . . E313: 22:02 2:6 P5. H ma. 8w. 5N... . . . . . mmfili...“ EuHTQB 2.30 Se. .153 . . . . mi... 3m. . . . . . avalwww 305v? 03:0 m3. Hnww. . . wow. OE. 3.... wwm. . . . bwffiw wkfliu? newé ma... H wmm. . . . EN. 3m. ma. ma? “mm. 8N. . . gwlu: whofiiu? “Eco 3;. Howm. 3N. 3N. .. . .. . . . . . . . . . wni|mfifl 3% 022w m3. fizz . 8w. m3. . . . . . . . . . . Qilmxrfiow :50 8.0. Q3. ma... own. 3...... Ne... Nwm. mmm. . .. . . . . .. ....$@l>w@ 30w 2.20 3o. “$2.. Mam. EM. mwm. 3+. 8i m3. mix fim. . . . emalfiv 3% 09:0 $5. Hmwm. fi». mum. N3. ma. $0. 5m. Nmv. N»... ....$N|£H 3.2. 02:0 woqwfiw. ~mo.Hm~m. mmoinlmf mgflfiww. amoiflofi. 53MB? Soilraw... omQHwmm. NNQHRM. mmqHfiw. 393:. . . ....=oc2w B? “w. Eon 33m 2m k2 um€o>< $2 ma“: NW2 32 52 0N2 0N2 22 22 £2 £2 :2 0929:‘ mcfiaw 2am wciam 2mm mcfiaw zwm wcimw 2am mciaw 2mm 9E3 wcimw wuwfiufi $.89 96A wcoq comfixukhoU we ~==oE< of =25 cowwum Mo ouuonwcw can. w 033w Factors Influencing Weights of Angora Fleeces 33 INDIVIDUALITY AND HEREDITY Individuality is defined in this Bulletin as the permanent differences between individuals of the same age and sex and of similar breeding. In other words individuality is the sum of the characteristics (aside from sex, age, and general type of breeding) which permanently distinguish one individual from another. The differences which are included under the term, individuality, can be separated for purposes of analysis into two classes; those which are due to differences in heredity and those which are due to non-hereditary causes. In actual practice it is usually im- possible to lay one’s hand on two goats, for instance, and say that one particular difference between them is due to differences in heredity and r that some other particular difference between them is not due to heredity. However, for practical purposes, it is of tremendous importance to know whether a permanent difference in some desirable characteristic is the result of hereditary difference or of environmental forces. This i! true, because, so far as is known at present, the effects of environmental forces are rarely or never inherited to any extent whatever. Therefore, if the permanent differences in fleece-weight are caused entirely by en- vironfnental forces, culling will improve the average of the flock upon which culling is practiced but will not improve the average of the off- spring of that flock. That is, the effects of selection will be confined to the animals actually selected and it will be necessary to begin the im- provement over again with each generation. On the other hand, if the differences are due to heredity, improvement will be made in the flock from which the culls were removed and the offspring of the selected an- imals will retain some of that improvement and will be superior to the off- spring of the rejected animals. Applying this general principle to the character studied in this Bul- letin, fleece-weight of Angora goats, we have the following situation: Within groups of the same age, sex, and general breeding, about fifteen to twenty per cent of the differences in fleece-weight have been found to be permanent.* The efficiency of selection in the generation which is se- lected is not affected at all by whether those permanent differences are hereditary or non-hereditary. However, the extent to which the kids of the selected does will have heavier fleeces than the kids of the rejected does will depend upon the extent to which the permanent differences be- tween the selected and rejected does are caused by heredity. Our present data are not enough to enable us to say positively what proportion of these permanent differences are hereditary but there are several indications that it is large. In the summary of Table 1 it will be noticed that the correlations for the registered does which were purchased from various breeders and were of diverse lines of breeding were larger than for the grade does and wethers, of which each group was bred by one breeder and therefore may naturally have been expected to have been *The square of the coefficient of correlation gives the degree of determination, and the square of the average coefficient of correlation in this case (+.415) equals .172 or in other words, 17.2% of the differences in fleece weights were permanent. 34 Bulletin N0. 320 Texas Agricultural Experiment Station more uniform in heredity than the registered does. The 10w correlations of the registered bucks are probably due to the fact that nearly all of these correlations concern kid shearings. Also the registered bucks had been rigidly culled to a certain standard of fleece whereas the other groups had not been so rigidly culled at the time when most of the shear- ings were made. There were hereditary differences between different groups of does (see Table 1 and the discussion immediately following) which would have caused the correlations to have been higher if the does had not been so rigidly separated into groups of the same general breeding. Grade does 1-154 furnish an excellent illustration of this. Grade does 1-51 were choice does purchased from one breeder’s flock and grade does 52-154 were average does purchased from another breeder’s flock. The former were distinctly superior to the latter in the amount of mohair which they pro- duced (as is shown in Table 9) and presumably their superiority was due largely to their better breeding although, of course, some of it may have been the result of a better environment while they were young. The co- elficients of correlation were calculated for the entire group of does 1-154 and are presented in Table 7 side by side with the correlations of the two separate groups of does, repeated from Table 1. ‘Table 7. Correlations Involving Grade Does 1-51 and Grade Does 52-154 in Separate Groups and correlations Involving All Grade Does 1-154 in One Group . . Grade Does Grade Does Grade Does Shearings involved L51 _ 54 1454 Fall of 1918 and Spring of 1919 . . . . . . . . . . .. .467 .469 .478 all of 1919 . . . . . . . . . . . . .. .494 .568 .533 Spring of 1920 . . . . . . . . . . .. .509 .545 .501 Fall of 1920 . . . . . . . . . . . . .. .530 .620 .558 Spring of 1921 . . . . . . . . . .. .239 .495 .375 ISpring of 1919 and Fall of 1919 . . . . . . . . . . . . .267 . .526 .652 Spring of 1920 . . . . . . . . . . .. .638 .739_ .779 Fall of 1920 . . . . . . . . . . . . .. .273 .504 .480 Spring of 1921 . . . . . . . . . . .. .458 .686 .733 Fall of 1919 and Spring of 1920 . . . . . . . . . . .. .300 .485 .577 Fall of 1920 . . . . . . . . . . . . .. .429 .590 .615 Spring of 1921 . . . . . . . . . . .. .203 .448 .591 Spring of 1920 and Fall of 1920 . . . . . . . . . . . .. .439 .312 .499 Spring of 1921 . . . . . . . . . . .. .804 .725 .840 Fall of 1920 and Spring of_1921 . . . . . . . . . . . . .364 .449 .574 Average coefficient of correlation . . . . . . . . .. +.428i.027 +.544i.019 +.586i.021 ‘Average constancy of dilferences in fleece weights . . . .i. . . . . . . . . . . . . . . . . . . . . . . . .__w_l8w._3l;f _ 29./6V%_____’M It will be seen from Table 7 that as a rule the correlation involving the whole group of does is higher than either of the correlations of the two separate groups of does at the same shearing. This merely means that there are a number of permanent differences in fleece producing ability between the two groups. When only one group is considered at a time these differences do not affect the correlation because the does of one Factors Influencing Weights of Angora Fleeces 35 group are all alike or nearly alike with respect to these, differences, but when the two unlike groups are combined in one correlation table then these differences between them do aifect the correlation to increase it. It is worth while to point out the practical bearing of this on the problem of selecting goats on the basis of fleece weights for increased mohair-pro- duction. The more permanent differences there are in any group of goats, the more successful any method of culling based on correct principles will be, and conversely, the more uniform a fiock already is, the less immediate improvement will result from culling. Grade Does 1-51 had already been culled by virtue of their having been selected one by one from a large fiock at the time of their purchase. Consequently they were more uni- form and their correlations were lower as a result of that uniformity. Grade does 52-154 were purchased without any individual selection and therefore were less uniform, their correlations were higher because there were more permanent differences between them, and culling would have resulted in proportionately more immediate improvement in them than in does 1-51. Culling the entire group of does 1-154 would result in proportionately still more improvement than culling either group by it- self, but the cause of this would be that culling the entire group would be largely a process of sorting out again nearly all of does 1-51 into .the better half of the fiock. That differences in uniformity are the causes of the differences in the size of the correlations for the three groups is borne out by the fact that the average of the coefficients of variability for the six shearings involved in Table 7 is 20.7% for does 1-51, 26.4% for does 52-154, and 28.1% for the combined group of does 1-154. Since culling will give better immediate results on flocks lacking in uniformity, it necessarily follows that goat-raisers whose flocks are less uniform than the groups of goats studied separately in this Bulletin will derive greater benefits from culling than the figures in this Bulletin would indicate, while those Whose flocks are more uniform will derive less ben- efit. We have no exact data on which to compare the uniformity of the groups of goats which make up the Experiment Station flock with the uniformity of the average fiock of goats in the state,* but it is the opinion of the authors that the different groups from the Experiment Station flock studied in this Bulletin are more uniform than the average fiock of An- gora goats found in this state. However, some goats differing in type are *If any goat-raiser desires to know how the uniformity of his flock in respect to fleece weight actually does compare with that of the Experiment Station fiock and therefore how far the results given in this Bulletin may apply to his flock, the authors will be glad to make the calculations and send him that information without charge provided he sends them the necessary data. Those data are the weights of all the fleeces produced by the goats about which he desires to know. For example the data may be given as follows: 1 fleece weighing 2.50 lbs., 3 fleeces weighing 2.75 lbs. each, 12 fleeces weighing 3.00 lbs. each, 11 fleeces weighing 3.25 lbs. each, etc. Weights should be accurate to a quarter of a pound or less, must not be averaged together, and must be of comparable individuals (that is. individuals of the same age, sex, and gen- eral breeding). It is desirable to have the weights of at least twenty-five or thirty fleeces, and fifty or more would give still more reliable results. _ Calculation of the actual coefiicient of correlation between the fleece weights of the same goats at different shearings will require more data but the authors _will be glad to make that calculation for any goat-raiser who would care to take the data and send it to the authors at College Station. This would be still more accurate than a 36 Bulletin N0. 320 Texas Agricultural Experiment Station kept in the Experiment Station flock for experimental purposes and it is l probable that there are flocks of Angora goats which are more uniforml: than the Experiment Station flock. ,7 The most important difference between the results obtained with l mohair weights and the results obtained with wool weights (as discussed in Texas Bulletin 311) is that the differences in mohair weights are not A so constant from shearing to shearing as the differences in wool weights. i On theoretical grounds there could be two explanations for this. First, - mohair fieeces may be influenced in weight much more by temporary en- . vironmental influences than wool fleeces are. Second, it may be that there ' are fewer hereditary factors influencing fleece weight in Angora goats ,1» and that the Experiment Station goat flock may have been hereditarily ‘i much more uniform than the Experiment Station flock of sheep. If the, a flock were perfectly uniform in heredity the only permanent differences in fleece weight must have been due to environment and if environment produced few permanent changes in fleece weight then the correlations would necessarily have been low. This second explanation is disproved as a complete explanation by two facts: first, there is nothing in the his- tory of the flocks to support it; and, second, if it were true, the variability of the mohair weights within each group of goats would be less than the variability of‘ the wool weights within each group of sheep. As a mat- ter of fact the variability was actually greater within each group of goats than within each group of sheep. No detailed study of the amount of variability was made but the average of the coefficients of variability for the 44 different shearings of groups of sheep which consisted of twenty or more individuals was 15.23i33% while the average coefiicient of variability for the 55 different shearings of groups of goats which con— sisted of 40 or more individuals was 22.81i0.37%. The difference is 7.581150%. Put into popular language this means that the sheep actually used in these studies showed only about two-thirds as much variability in their fleece weights as the goats did and that the difference is so great (more than fifteen times its probable error) that it cannot reasonably be knowledge of the uniformity of his flock in telling the goat-raiser how much ‘it would pay him to cull his flock. The data should be in some such form as the following: Fleece Weights Goat No. f? ?|_‘“'*€"__ 5 Spring 1925 Fall 1925 1 ; 4.25 l 4.0 2 2.75 3.0 3 3.0 3.75 etc. ‘ etc. _. etc. i The correlation can be calculated for as few as fifteen or twenty goats but it is, hardly worth while to do it for less than forty or fifty, and still more would make the results more dependable. ' Factors Influencing Weights of Angora Fleeces 37 supposed to be accidental, and a difference which would be almost as large would be sure to be found again if a similar experiment were re- peated. We have, then, established two facts: first there is greater variability among the weights of mohair fleeces than among weights of wool fleeces ' at a given shearing. Second, the weights of the wool fleeces are more con- stant from one shearing to another than the weights of mohair fleeces. Between these two facts there is no escape from the conclusion that temporary environmental forces have much more influence upon mohair fleece weights than upon wool fleece weights. We have not collected and analyzed enough data to know whether this greater variability in weight of the mohair fleece is due to a greater variability in its shrinkage per cent or to a greater variability in the actual weight of the scoured mo- hair, or to a combination of both. The situation with respect to heredity and selection for heavy fleeces in Angora goats may be summarized as follows: A goat inherits the ability to produce a certain weight of mohair under ordinary environ- mental conditions. If the environmental conditions are better than the average, more mohair will be produced, but less will be produced if the conditions are below average. These environmental conditions may be different enough.to influence very differently individual goats which are of the same age and sex and have even been allowed to browse in the same pasture during the same season. Therefore, selection for heavier fleeces strictly on the basis of the actual weights of fleeces produced will result in some mistakes although the correct decisions will outnumber the mistakes and some progress will be made toward heavier fleeces not only in the generation actually culled, but also in the offspring of that generation. Culling on the basis of fleece weights is better than no culling at all but it seems reasonable to suppose (although the data to prove‘ it are lacking) that a man well-acquainted with Angora goats could, by ob- serving the character, quality, length, and density of fleece and the ex- tent to which the whole body is covered with mohair, cull a flock of Angora goats for increased mohair-production more accurately than can be done by actually weighing each fleece. The actual weight of the mo- hair fleece is not as accurate an index to the inherited ability of a goat as the weight of the wool fleece is to the inherited ability of a sheep be- cause the weight of the mohair fleece is influenced much more by tem- porary environmental forces than is the weight of the wool fleece. 38 Bulletin No. 320 Texas Agricultural Experiment Station PART III THE INFLUENCE OFuAGE AND SEASON UPON THE WEIGHT OF THE MOHAIR FLEECES I It was possible to study individuality without taking either the effects of age or season into consideration, merely by using in any one correla- tion table only goats of the same age and sex which were sheared the same two seasons. It is not, however, possible to study the effects of age and season separately. This is obviously true because if shearing records of the same goats at different ages are used, they will also be influenced by differences in season, while, if we compare goats of diflerent ages, the same year, their individual mohair producing abilities may be different. It is possible, however, to study the combined influence of age and sea-T, son and, if the study is carried on with enough goats over a great many years, accurate knowledge can be secured of the exact effects of age and seasonal changes. i The first two shearings reported in this Bulletin (those for the spring of 1917 and the spring of 1918) were of Itwelve months’ growth of mohair and were produced in a different locality and therefore it seems hardly Y‘ fair to compare them with the later shearings although they are included in the tables and figures. The 1918 fall shearing of the foundation reg- istered does consisted of only about five months’ growth of mohair and therefore cannot fairly be compared with the later shearings. The shear- ings of the other goats in the fall of 1918, and all later shearings of all goats except the kids, consisted of six months’ growth of mohair, varying not more than ten days from an exact six months in any case. Most of the kids were dropped in April or very late in March and therefore the ' kid shearing included on the average a little more than five months’ growth of mohair. Thus We have ten successive six-month shearings suitable for comparison with each other and these provide sufficient data to answer most of the questions which may arise about the effects of age and sea- son upon the Weight of fleece. The effects of age upon the weights of wether fleeces are not completely revealed by these data because none of the Wethers were kept past three years of age, but for economic reasons this point is not very important since not very many wethers are ordi- narily kept on ranches past this age. .92» m. .25 Hmmmamaa o». >wa mum mammo: o: $5 imam» o» $5 1023a Qfimawx. maa awuaammam m: baaaamammam o0“. $5 mama M51 $15 mramammw. 85am mm $5 “$3025 $3.1m.» m: m: axaaww s; 02m m9: macaw? .25 mmmcamaa o». mbmmimcmmmaw mm awamcmamv. 0 0...”... gm... s m... 9 m... o . m... 1 m... 2 m... mo... 5a..“ “mm “ma. my. mm an ma aw mm ma ma ma m” LS1 LS1 F1 S1 F1 S1 F1 S1 F1 S1 F1 S1 Gamma moam 0mm.m00....... 00.0 0.00.0 5P0 3.... 000.0 Cmh :00 00.0 Gamma moam §m-@mm....... 0.0.4 000.0 5.70 Cm.» 533m :00. H0100 5»; Gamma moam ammmrfili... __ 3.» 000.0 000k 00.0 $00.0 Ema Gamma moam 0.27:»? . . . . . 00L 000.0 Sm.“ 000.0 Gamma moam 53-2.8. . . . L i 00.0 000.0 Gamma <140 3L -120 73 -1oo g -so 7t / -so r >40 ;Z ~20 Fall Spring Fall Spring Fall Spring F111 Spring Fall Spring 1918 1919 19I19 1920 1920 1921 19l21 19.22 19.22 19.23 Figure 5. The influence of age and season on the weight of the fleeces produced by the grade does born at the Station. Weights are expressed in percentages of the weight of fleece produced by the same individuals at the spring shearing when they were one year old. Grade wethers Born in 191B _ _._ -— Grade wethers Born 1n 1919 _ __ _ _. _ Grade Wethers Born in 1920 ——6—0—‘— Grade wethers 50m 1n 1921 L —-— — -—— Grade wetners Born in 1922 -18o j,‘ >160 7S >140 {.1 -12o g .100 y; /g/a/ // / ~80 y”, 8 1% I N O u§ Fall Spring Fall Spring Fall Spring Fa 11 Spring Fall Spring 1918 19_19 19,19 19_20 1920 19,21 19,21 19,22 19,22 1923_ Figure 6. The influence of age and season on the weight of the fleeces produced by the grade wethers born at the Station. Weights are expressed in percentages of the weight of fleece produced by the same individuals at the spring shearing-when they were one year old. ‘ 42 Bulletin N0. 320 Texas Agricultural Experiment Station -1 a i Registered Does Born in 1919 Registered Does Born in 1920 - — — - - - Registered Does Born in 1921 ,20o i; i.» Registered D095 Born in 1922 -1eo 7t >160 a -l4o g -120 g -1oo g4 -ao 7, r60 fi ~10 $2 '29 75 . Fall spring Fall SPYME Fall "pring F811 spring Fall Spring 1918 19,19 19,19 19,20 19,20 39,21 19,21 1932 19,22 19;: Figure '7. The influence of age and season on the weight of the fleeces produced by_the registered does born at the Station. Weights are expressed in percentages of the weight of fleece produced by the same individuals at the spring shearing when they were one year old. - 22o 7t _ Foundation Registered Does i i i Grads noes nos. 1 - 51 -180 7K - - - — — — — Grads noes mos. 52 - 154 —-—9—-0-e— Grade Does nos. 292 - 416 - 16o 7.1, - 140 7; - 12o =7, - 100 a k 80 ‘If, - so g L40 7; - 20 1.0113 7a 3 ring F811 spring Fall Spring F811 Spring F311 Spring F911 Sprinx igm 19,111 19,19 19,19 19,20 19,20 9,21 19,21 19,22 19,22 19p Figure 8. The influence of age and season on the weight of the fleeces produced by_the four groups of purchased does. Weights are expressed in percentages of the weight of fleece produced by the same individuals at the spring shearing of 1919. Grade does Nos. 292-416 were two years old and the others were older at the time of that shearing. Factors Influencing Weights of Angora Fleeces 43 a Grade Does 30m in 1918 4- -_- -- Grade Does Born in 1919 _ _ _ _ _ - Grade Does Born in 1920 —o—_¢_e_ Grade Does Born in 1921 -_- _ -_. Grade Does Born in 1922 - 5.0 lbs. - 4.0 lbs. ~ 3.0 lbs. -2.0 lbs. -1.0 1b. ran Spring F811 sprins’ Fall Sprins F211 Spring Fan Spring 191s 1919 19119 19,20 1930 19,21 1121 19,22 19.22 19;; Figure 9. The influence of age and season on the weight of the fleeces produced by the grade does born at the Station. Data are taken from Table . Grade wethers Born in 1918 Grade Weathers Born in 1919 — — — — — —Grade wethers Born in 1920 ——+—0—0—Grade Wethers Born 1n 1921 Grade wethers Born 1n 1922 .5.o lbs. 74.0 lbs. -3.0 lbs. // /"/ / -2.0 lbs. -1.0 lb. i-‘all Spring Fall 3pr1ng Fall Spring Fall jpring F311 Spring 1918 19,19 19,19 19,20 1920 1931 19,21 1922 1932 13,23 Figure 10. The influence of age and season on the weight of the fleeces produced by the grade wethers born at the Station. Data are taken from Table 9. 44 Bulletin No. 320 Texas Agricultural Experiment Station Registorou Leas 30m in 1919 1 Registarzc 309: 10m in 1920 — -— -— — ‘Yegtistn-ad Doss Porn in 1921 5 __ l_ -——6——e—-<>—Re;',ist0rod Boos 50m in 1922 - .u us. ~4.0 lbs. - 3.0 lbs. ~ 2.0 lbs. -1.0 1b. Fall Spring Fall Sprine F811 spring Fall {ipring Pall Jpring 19,19 1919 1919 19,20 1930 19_21 19,21 1932 19g: 192:5 Figure 11. The influence of age and season on the weight of the fleeces produced by the registered does born at the Station. Data are taken from Table 9. T ,6“, ‘b5 Foundation Registered Does i- ——— ——— Grade Doos NOS. 1 - 51 - — - — — — Grace Dues Nos. 52 - 154 -—o--e—e~ crane Does You. 292 - 416 -5.0 lbs. -4.0 lbs. 45.0 lbs. -Z.O lbs. -1.0 1b. 1.0118 Spring Fall Spring Fall spring Fall Spring Fall Spring Pall spring 19H 191s 19,19 19,19 19,20 19,20 19p 19,21 1932 19,22 19,23 Figure 12. The influence of age and season on the weight of the fleeces pro- duced by the four groups of does which were purchased. Data are taken from Table 9. Factors Influencing Weights of Angora Fleeces 45 The combined influence of age and season upon the weight of fleece produced by the different groups of Angora goats is shown in Tables 8 and 9. The data given in Table 8 are presented graphically in Figures ' 5 to 8 while Figures 9 to 12 show graphically what is presented in figures in Table 9. The difference between Tables 8 and 9 is slight but requires a word of explanation. The figures in Table 9 are obtained by averaging to- gether the Weights of all the normal fleeces produced by each group. The figures in Table 8 are obtained by comparing the average weight of the normal fleeces produced at any shearing with the average weight of the normal fleeces produced by the same individuals at the spring shearing when they were one year old or, in the case of the purchased does, at the spring shearing of 1919. An illustration will make the difference in the methods plain: In the first group of grade does born at the Station (Nos. 155- 291) there were 47 normal fleeces sheared in the fall of 1918 and 48 nor- mal fleeces sheared in the spring of 1919 but only 45 of these were from goats which produced a normal fleece both times. Two of the 47 which were sheared in the fall of 1918 died before the spring shearing of 1919 while the shearing records for the fall of 1918 were lost for three which were sheared in the spring of 1919. The figures for these shearings in Table 9 are the average of the weights of the entire 4'7 and 48 fleeces res- pectively, but the figures in Table 8 are a comparison of the averages of the 45 fleeces which came from the goats which produced a normal fleece at both shearings. When the irregular records are of fleeces of average weight both methods will give the same result, but when the irregular records are of unusually heavy or unusually light fleeces the results will be slightly different. It will be seen from the Tables and the Figures that the results from the two methods differ only slightly. Table 8 is the more accurate because the influence of differences in individuality is eliminated from it, but its figures are based upon slightly smaller numbers and it has the disadvantage that the average production of one group cannot be compared directly with that of another because the average fleece weights at their spring yearling shearings (which are taken as 100% in Table 8) may not have been the same. One of the first features which will be noticed about Tables 8 and 9 and Figures 5-12 is that the fall shearings are heavier than the spring shearings. There are some exceptions among the purchased does but the difference is usually rather large, the fall fleeces being in most cases ten to thirty per cent heavier than the succeeding spring fleeces. The dif- ferences are not that great among the purchased does but are greater among the wethers and some of the younger groups of does. Fall fleeces and spring fleeces had about the same length of time in which to grow but the fall fleeces were grown in periods of higher temperatures, more suc- culent feeds, and (usually) more abundant feed. The results indicate that a goat grows mohair not so much as a response to cold weather, but more as the result of an abundant supply of the right kind of food. It is possible that the fall fleeces have a higher shrinkage due to their hav- ing been grown in a warmer season and therefore containing more sweat 46 Bulletin N0. 320 Texas Agricultural Experiment Station and yolk, but to offset this there is the fact that the goats were dipped during the periods when their fall fleeces were being grown and this would probably have tended to wash out enough sweat and yolk to lower the shrinkage noticeably. A study of the shrinkage of fall and spring fleeces of wool and mohair is being made at the Wool Scouring Plant of the Texas Agricultural Experiment Station at College Station but not enough data have been collected to serve as the basis of any conclusions as yet. However, it does not seem possible that a difference in shrinkage can entirely explain the difference in the weights of fall and spring fleeces since the shrinkage of a‘ mohair fleece is ordinarily from ten to twenty percent, whereas many of the average fall fleeces exceeded the average weight of the following spring fleeces by more than thirty per- cent. Therefore, it is clear that more actual clean mohair was usually produced at the fall shearing than at the spring shearing. Abundant food of a good quality seems to be more important than low temperature in promoting the growth of mohair. It should be added that, from the time they were two years old, most of the grade does raised one or two kids each year. The kids were dropped after the spring shearing and weaned before the fall shearing (the shearing dates were near March 20th and September 20th each year), and therefore the effects of suckling these kids should fall entirely on the fall shearing-of their dams rather than on the spring shearings. This probably is a complete explanation of the greater difference found between the spring and fall shearings of wethers than between the spring and fall shearings of mature does. The effect of sex is very marked, the average weight of fleece pro- duced by the wethers being greater than that produced by the grade does of the same age and breeding at every shearing except one. In that one (the kid shearing of the grades born in 1920) the average fleece weight is exactly the same (1.30i-.02). The difference in the average weights of fleeces produced by does and wethers does not become a large one, how- ever, until they are two years old, that is, until the does begin producing kids. Whether barren does would produce as large fleeces as wethers was not determined because there were so few barren does in the Station flock. The efl"ect of age is very marked and very great for the first three shearings but after that there seems to be very little change due to age, at least until extreme old age is reached. Extreme old age may be the explanation for the decreasing fleece-weight of the foundation does at the last three shearings, since the very youngest of them were five years old‘ and most of them were eight or more at the time of the 1923 spring Sljjear- ing. The first or fall kid shearing is very light, averaging only £53,670 of the second or spring kid shearing for the grade does, 59.4% for the wethers, and 71.0% for the registered does. Even these figures (‘taken from Table 8) are a little higher than normal because of the veryf- light shearing in the spring of 1922 (to be discussed later), which makfeg the kid shearing in the fall of 1921 appear larger on the percentagei,‘ basis. In no case is any later shearing as light as the kid shearing. Factors Influencing Weights of Angora Fleeces 47 The second or spring kid shearing is not as a rule quite equal to the average later production of the goat. There are eighteen fair compar- isons between second or spring kid fleeces and subsequent spring fleeces and in only three of them does the second or spring kid fleece out-weigh the later one. This means that as mohair-producers goats are not quite mature at one year of age. The goat reaches its maximum capacity as a mohair-producer in the fall when it is one and a half years old. At least this is true of the does but only one group of wethers was kept long enough tobe sheared in the fall when they were two and a half years old and that group sheared practically the same amount in both its yearling fall shearing and its two-year-old fall shearing. One group of does (registered does 50-93), according to the method of figuring used in Table 9, sheared slightly more in the fall when they were three and a half years old than in the fall when they were yearlings, but according to the more accurate method used in Table 8 the fall yearling shearing for this group was larger than any later shearing for it. The influence of age upon fleece weight thus seems almost identical in Angora goats and in sheep, as discussed in Texas Bulletin 311. In both cases the fleece production during the first year of life is less than normal; in both cases maximum fleece production is attained by the females during their second year of life; in both cases there are indications, al- though not enough data for absolute proof, that the wethers can con- tinue to produce as heavy fleeces later in life as they do in their second year, and, finally, in neither case do the effects of extreme age become very marked, if evident at all, until the animals reach at least seven or eight years of age. The data on which this present Bulletin is based are too few to justify the establishing of very exact figures as to the effect of age on fleece- weight, or to permit the working out of an exact equation which would show the relation between age and fleece-weight. Data on many more groups of goats for different years will be needed for that. However, the data in this Bulletin (as presented in Table 8) are the most complete data avail- able and therefore they have been averaged in Table 10 and presented graphically in Figure 13. The probable errors of those averages will furnish an’ approximate indication of their accuracy. No probable errors could be calculated for the last two ages of wethers because the figures for those ages are based upon only one group of goats. No attempt was made to weight the figures from Table 8 in proportion to the number of goats which each figure concerned because inspection of Table 8 shows that there was more variation from season to season than there was be- tween different groups at the same seasons. For example, all kid fleeces were unusually light in the fall of 1918 and all kid fleeces were unus- ually heavy in the fall of 1921, etc. Therefore, it seemed best to treat each season as a unit regardless of the number of fleeces upon which its average was based. The grade does and the registered does were treated as separate units. The percentages in the last four lines in Table 10 were 48 Bulletin N0. 320 Texas Agricultural Experiment Station obtained indirectly from the figures in Table 8 for the three purchased groups of grade does, by assuming that the fleece Weights of the pur- chased groups in the spring of 1919 bore the same relation to their sec- ond or spring kid fleece weights as the average fleece weight of the sta- tion-raised does (when they were the same age as the purchased does were in the spring of 1919) did to their second or spring kid fleece- weight. It is the authors’ belief that these average figures represent rather accurately the eifect of age upon fleece-weight except in the case of the last two figures for wethers and the last figure for does, which are almost certainly too low. Table 10. The Effect of Age Upon Average Fleece-Weight. (Expressed in percent- ages of the yearling spring fleece. Figures taken from Table 8 and averaged). _,_ , 7 _ 17} ,1 7 Age Does Wethers Kid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 63314.3 59.41 4.9 Yearling Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.0 l 100.0 Yearling Fall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167.-313.3 172.81 8.0 Two-year-old Spring . . . . . . . . . . . . . . . . . . . . . . . . 117.214.0 136.5116.2 Two-year-old Fall . . . . . . . . . . . . . . . . . . . . . . . . . . . 144.515.6 157.3 Three-year-old Spring . . . . . . . . . . . . . . . . . . . . . .‘ 124.215.6 153.8 Three-year-old Fall . . . . . . . . . . . . . . . . . . . . . . .7 . . 141.4182 Four-y_ear-old Spring . . . . . . . . . . . . . . . . . . . . . . . 114.515.’? Four-year-old Fall . . . . . . . . . . . . . . . . . . . . . . . . . . I 120.6122 Five-year-old Spring . . . . . . . . . . . . . . . . . . . . . . . 118.112.2 Five-year-old Fall . . . . . . .» . . . . . . . . . . . . . . . . . . . 121.715.8 Six-year-old Spring . . . . . . . . . . . . . . . . . . . . . . . . .| 104.712.3 One interesting result caused by a combination of the effects of age and season is to be observed in the case of the kids born in 1921. A severe drouth began in June 1921 and continued until late in March 1922. The effects of the drouth began to be evident in the pastures by mid-summer of 1921 and it will be noticed that the 1921 fall shearing was an un- usually light shearing for all goats except the kids. The kids had been weaned only about a month before that shearing and had evidently been receiving almost all their food from their mothers’ milk and therefore had been protected from the effects of the drouth as shown by the fact that their fleeces were unusually heavy that fall as compared with other kid fleeces. That it was their mothers’ milk which protected them from the effects of the drouth is shown by the fact that the following spring their fleece-weights were unusually low for yearlings. They had gone through the fall and winter of the drouth without any milk from their mothers, since they had been weaned before the fall began, and there fore they felt the effects of the drouth and resultant scarcity of feed just as the other goats did. This is an excellent illustration of the way young Factors Influencing Weights of Angora Fleeces 49 animals are guarded naturally against effects of an unfavorable enviigon- ment until after they are weaned, their mothers evendrawing on 1;! e_1r own reserve food-supply for some time before decreasing very muc 1n milk yield. It will be seen by comparing these Tables and Figures with those_in Texas Bulletin No. 311 that the mohair weights are more subjecfi to in- crease or decrease with unfavorable seasons than the wool weig ts are. Thus, although all the groups of goats do not agree at every shearing, it will be seen that in general among the fall shearings, that for the fan Average fleece weight of does, expressed in percentage of the yearling spring fleece , — — — -— — Average fleece weight of wethers, expressed in percentage of the yearling spring fleece 40- 20 - Fall spring Fail spring he'll spring Fall spring 175.11 Sprling Pali). spring . r I’ Kid Yearling Two-year-old l Three-year-old Four-year-old l Five-year-old I Figure 13. The effect of age upon average Fleece weights. (This is a graphical pre- sentation of the data shown in Table 10 of 1922 is unusually heavy, while those for the fall of 1918 and the fall of 1921 are below the average. Also, among the spring fleece weights, that for the spring of 1922 is distinctly low and that for the spring of 1923 is high except in the case of the purchased does, which were getting old by that time. There was a short but rather severe drouth from May to October in 1918 and a long severe one from early June 192.1 to March 1922 and it will be seen that the light shearings are the three following those drouths, that is, the shearings for the fall of 1918 and fall of 1921 and spring of 1922. The fleece weight for the spring of 1920 is slightly below the average and it is interesting to note that the February and March rains (on which depends so much of the early growth of weeds upon which the goats feed) totalled only 0.76 inches for that season. Of course rainfall is not the only factor controlling the amount of feed which is produced in that region, but on this one ranch under a rather uniform system of management and carrying about the same amount of livestock from year to year, the amount and distribution of the rainfall are the" most important factors governing the production of feed. The amount and monthly distribution of rainfall as officially recorded at Substation No. 14 during the first five years for which the records were taken are given in table 11. 50 Bulletin N0. 320 Texas Agricultural Experiment Station Table 11. Monthly Rainfall in Inches, Texas Agricultural Experiment Station, Substa- _ tion No._14, Sonora, Texas 5 1918 1919 1920 1921 1922 1923 l _. _.__. January . . . . . . . . . . . . . . . . . 2.28 2.33 1.13 .65 1.55 February . . . . . . . . . . . . . . . . 1.45 .36 1.49 .10 3.98 March . . . . . . . . . . . . . . . . . . 1 2.15 .40 3.17 2.13 2.59 April . . . . . . . . . . . . . . . . . . . 2.49 .32 .84 5.19 4.09 May . . . . . . . . . . . . . . . . . . . . 3.24 3.58 2.59 4.76 1.03 June . . . . . . . . . . . . . . . . . . . . ..l 1.21 5.48 4.67 2.66 4.14 July . . . . . . . . . . . . . . . . . . . . .00 .95 1.96 .45 1.30 August .61 1.98 6.09 1.05 3.23 September 1.90 9.14 2.24 .64 2.14 October . . . . . . . . . . . . . . . . . . 5.50 2.44 2.78 .38 3.18 November . . . . . . . . . . . . . . . ..! 1.90 | 1.16 | 1.62 , .40 | 1.93 December . . . . . . . . . . . . . . . . 1.70 I .51 .15 .30 .05 The only sure conclusion which we feel justified in drawing from Tables 8, 9, and 11, in regard to the influence of seasonal changes ‘on weight of fieeceis that these seasonal changes do affect the mohair weightsgmore noticeably than they do the weights of the fleeces produced by sheep. Drouths, presumably because of the scarcity of feed which results from them, cause a distinctly lighter mohair fleece to be produced. OTHER CONSIDERATIONS IN CULLING ANGORA GOATS The amount of yolk or grease that should be carried in the fleece of mohair is at the present time a debatable point among the Angora goat breeding fraternity in the United States. A number of scouring tests con- ducted at this Station have shown that mohair fleeces have shrunk as low as seven percent and as high as twenty-eight per cent. Mohair buyers representing eastern houses in Texas have not up to the present time made a practice of purchasing mohair on a clean basis. Usually kid hair is sold at a certain stipulated figure while all grown hair regardless of clean yield generally goes at a flat price. Under the present system of marketing, the breeder producing the mohair with a heavy shrinkage reaps a larger profit than the one who produces a fleece possessing plenty of character and quality but with a lighter shrinkage. Mohair manufacturers do discriminate, however, against fleeces con- taining a large amount of kemp, since it cannot be dyed evenly. There- fore, even though there is still some question as to the amount of yolk or grease that a mohair fleece should carry, the breeder should reject all bucks carrying a considerable amount of kemp on back or breech. The Factors Influencing Weights of Angora Fleeces 51 authors’ experience has been that there is a tendency among the extremely oily-fleeced bucks to show an abundance of kemp, although in a few highly improved flocks producing the heavier shrinking fleeces, kemp has been found to be almost entirely absent. Due to the fact that first-quality kid hair possesses more quality than any other grade of mohair offered on the market, and brings the highest price, it is only reasonable then to suppose that the hair from the grown goat which most nearly approaches the kid hair in character, quality, and condition should be the most valuable kind of hair for the breeder to produce. This Station plans to investigate this question thoroughly. In the meantime, breeders are reminded that in culling of their Angora goat flocks, individuals possessing the following weaknesses should be removed from the flock: 1—Over-shot or under-shot jaw. 2—Heavy covering of kemp on back or breech. 3—Weak constitution or too small in carcass. 4—Straight fiuify hair. 5--Bare bellies. 6—Colored eyelashes or fleeces. The mohair should be quite uniform in quality from shoulder to breech and the ringlets should be Well formed and distinct. Uniformity in length of mohair over the various parts of the body is important. It is evident that culling must be done at shearing time or just be- fore, if it is to be practical for the producer of mohair as well as for the breeder of registered goats. By marking the undesirable goats with special wool paint as soon as they are sheared, this culling can be done without keeping any extra records. All that it will require is a little extra paint and the time of the man who is doing the culling in the shearing shed. It is not necessary to cull out exactly half of the flock (as has been mentioned in the illustrations in this Bulletin). If only one- fourth of them are culled out the benefits will still be large enough on the average to pay handsomely for the trouble of culling. On the other hand the breeder of registered goats may want to pick out only a small portion of his flock from which to raise his best breeding stock. Each man can make his culling standard high or low to suit his own situa- tion. The essential point is that such culling will, on the average, steadily raise the standard of the flock and its results will be profitable enough to justify its becoming part of the customary practice of mohair-pro- ducers. 52 Bulletin N0. 320 Texas Agricultural Experiment Station SUMMARY 1. Texas contains more than half of all the Angora goats in the United States. The principal source of revenue from these goats at the present time is the mohair which they produce; hence the importance of finding out how to breed and manage goats so that more and better mohair will be produced. 2. This Bulletin presents and analyzes a large amount of data with respect to fleece weight. The importance of other characteristics than weight of fleece (for example, fineness, luster, condition, freedom from kemp, etc.) is not underestimated but those things are not discussed in this Bulletin merely because of the lack of any such large amount of data ‘dealing with them as is available on the subject of weight of fleece. 3. The data on which this Bulletin is based consists of the individual weights of the twelve-month fleeces shorn at Substation No. 7, Spur, Dickens County, in the spring of 1917 and spring of 1918 and of the six- month fleeces shorn at Substation No. 14, Sonora, Sutton-Edwards Counties, from the fall of 1918 to the spring of 1923, inclusive. In all there were 1166 different goats which were sheared at least twice, some of them being sheared as many as twelve times. A number of others which were sheared only once are included in Table 9 in the study of the influence of age and season on the weight of fleece. 4. Individuality is defined, for the purpose of this Bulletin, as the permanent differences (with respect to the weight of the fleece which they produce) between individual goats of the same age and sex and of tho same general breeding. The influence of individuality on fleece weight is studied by means of correlation tables. 5. There are a total of 302 such correlation tables and the average value of the coefficients of correlation is +.415i".0O8, which means that, on the average, 17.2% of the differences in the weight of fleeces produced by goats similar in age, sex, and general breeding, are permanent through- out the lifetime of those goats and therefore are subject to selection. 6. There is a great deal of variation in the size of the correlation. The largest negative correlation is —-.346i.130 and the largest positive correlation is +.861i.030. There is a slight but probably not significant tendency for the correlations involving the largest numbers of individuals to be the highest. 7. Individuality is much more important with some groups of goats than with others, and, consequently, culling will be more profitable with some groups than with others. 8. Fall fleeces from the same goats tend to resemble each other in weight and spring fleeces from the same goats tend to resemble each other in weight more closely than fall fleeces tend to resemble spring Factors Influencing Weights of Angora Fleeces 53 7 fleeces in weight. There is some indication of a hereditary basis for this, ~ since it was much more pronounced in the grade does and wethers than in the registered does. Since fall shearings are heavier than spring shearings, this makes it evident that the fall shearing is better than the spring shearing as a time at which to cull goats for increased mohair production. 9. Shearings separated by short intervals of time resemble each other in weight more closely than those separated by longer intervals, when allowance is made for the greater resemblance in weight between different fall shearings and between different spring shearings than between fall and spring shearings. 10. Permanent differences in fleece weight show up less accurately at the first shearing than at later shearings, and show more accurately at the fall yearling shearing than at any other age. Therefore, culling will be most effective if done at the fall yearling shearing. 11. Seasonal conditions seem to have little or no influence upon the size of the correlations between fleeces produced at different times. There is some slight evidence that such correlations are highest when they con- cern seasons when production is highest but this evidence is not con- elusive. ~this in the case of the wethers and less in i! only. The first or fall kid shearing is very j 0nd or spring kid shearing is a a thus indicating that goats have not quite reached maturity in fleece-pro- _ does produce. 12. In flocks less uniform than the Experiment Station flock, culling would be more immediately effective than in the Experiment Station flock. In flocks more uniform than the Experiment Station" flock, culling would bg less effective. Goat-raisers may find out how the uniformity of their flock compares with that of the Experiment Station by sending the nec- essary data to the Experiment Station. 13. Environmental conditions cause much more variation in the weight of mohair fleeces than they do in the weight of wool fleeces. I /\ - “"14. Fall fleeces are heavier than spring fleeces. The difference varies quite a great deal but the fall fleece is ordinarily ten to thirty per cent heavier than the succeeding spring fleece. The difference is greater than the case of mature does which are raising one or two kids. 15. Wethers produce heavier fleeces than does but the difference is not very great until after they are two years old; that is, until the does . begin producing kids. marked on the first three shearings light, averaging only sixty heavy as the second or spring kid fleece. The sec- little lighter than later spring shearings, 16. The effect of age is very to seventy per cent as The fall yearling fleece is the largest one the large in the case of the wethers but their duction at one year of age. It is also very 54 Bulletin No. 320 Texas Agricultural Experiment Station later fall shearings may possibly be still larger; the data are not con- clusive on that point. 17. The effects of old age on fieece weight do not become marked until the goats are at least six or more years old. 18. The eifects of age on fieece weight are very similar in shee; and goats. In both sheep and goats, fieece-production is not up to nor- mal during the first year of life; in both, the females attain maximun‘. fleece-production during the second year of their lives and in later year: produce slightly less than in the second year but more than in the firs1 year until extreme old age; in both, there is some evidence but not con- clusive proof that the wethers can in later years continue to equal or exceI the fieece-production of their second year; in both, the effects of old ‘age on the fleece-production of the females are not evident until the female: are at least six or more years old. 19. Drouths and the resultant scarcity of food lower the weights o1 fleeces‘ from Angora goats more than the weights of fleeces from sheep under the same conditions. 20. On the basis of these facts it is recommended that every mohair- producer should adopt a regular policy of culling his flock. Such a policy rightly carried out will result in an increase in the average weight oi fleece which his flock produces and an improvement in the character and quality of the mohair produced. REFERENCES ON ANGORA GOATS Black, W. L., 1900. A New Industry or Raising the Angora Goat and Mohair for Profit. Keystone Printing Co., Ft. Worth, Texas. Chapline, W. R., 1919. Production of Goats on Far Western Ranges. United States Department of Agriculture, Bulletin No. 749. Schreiner, S. C. C., 1918. The Angora Goat. Longmans and Co., New York. Williams, G. P., 1921. The Angora Goat. United States Department of Agriculture, Farmers Bulletin No. 1203.