V . ., ' §;?.-a DIM IIEElQS-l J. I Cattle Perf II felection Based on Gain ing A bility a?‘ Scales tell the rate of weight gain. A in cooperation with the UNITED STATES DEPARTMENT OF AGRICULTURE P TEXAS AGRICULTURAL EXPERIMENT STATION R. D. LEWIS. DIRECTOR. COLLEGE STATION. TEXAS DIGEST While cattle will always have a prominent place in Texas agriculture, the beef production indu try must rely on technological advances to keep pace with other agricultural fields. Results of a con tinuing study at Substation N0. 23, at McGregor, Texas, of the ability of young cattle to grow and ga' weight form one of the most important advances made in recent years. ' Gaining ability as a basis for selection is of major importance for efficient beef cattle" productio Selection for characteristics that are not of economic importance reduces progress in selecting for th important ones. Gaining ability is a trait high in heritability and selecting for it permits progress t be made in herd improvement. Tests for selection for gaining ability with large numbers of animals are being made at the M Gregor station. Results to date indicate that heritability of gaining ability is 50 to 55 percent, a tively high value which indicates that selection can be effective in increasing the gaining ability of b cattle. ' The following recommendations are made to the breeder and producer: Keep cattle from which selections are to be made under practical conditions for production. Select at a practical age for production (usual market age). Use actual weights. Determine ages of calves by recording the date of birth. Compare each animal on the basis of gain in relation to gain of others at the same time and =5 der the same conditions. a Select on the basis of weight gain. Select on the basis of the individual’s record. ‘Select both sexes — sires more carefully. Keep selection simple and sound. When buying, get tested, high-gaining sires. Gain ratios of Brahman sires and all of their heifer offspring from Hereford cows which were in the 1954-55 McGregor gain evaluation test. " Sire Gain ratio No. of offspring Average gain ratio of of sire from each sire each sire s offspring t, A 123 5 120 B 113 7 112 C 106 6 106 ‘ D 105 8 94 E 105 6 87 ' F 101 4 77 This example from the most recent McGregor gain test was chosen because for the firs ~ time several tested sires were represented and each had several heifers entered as a progen test. Note that the ranking of the progeny groups in gaining ability is the same as the rank; ing of their respective sire’s gaining ability record. On the average, high gaining sires prQ duce high gaining offspring. This is just an example, but it illustrates the findings of s : ’ tistical analyses. V‘: RESULTS OF TESTS ON THE GROWING ABILITY young cattle form the basis for one of the most ortant advances in beef cattle production in t years. An inherently healthy, vigorous, i. atically adapted animal that is highly fertile ecessary for the ranchman. At the same time, g gh quality product is necessary for the packer '- consumer. f This bulletin is the second of a series report- ' the results of investigations with beef cattle Substation No. 23 at McGregor, Texas. The a of the series, Bulletin 790, was based on " luation Tests for Gaining Ability.” Others include: selection in the McGregor station ’ O based on performance; carcass evaluations ‘Hereford and first-cross Hereford x Brahman ‘rs; Weight for age at Weaning; regularity of ding; use of heat tolerance tests; and hybrid r. Permanent improvement in beef cattle results _ugh selecting superior animals and stabiliz- ‘ their inheritance through breeding. Manage- t and feeding should not be overlooked, but ire productive cattle should be bred. Growing f ity is the key to fast, economical beef produc- Ii The theoretical basis Was given in the first etin of this series (Warwick et aL, 1955), p etin 790. Bulletin 815 presents the actual . -producing performance records of the off- 'ng of selected high-gaining parents. Specific mmendations to the breeder include: f What to select for and Why. _. What not to select for and why. How to get records on animals for use in se- ion. I The amount of success that can be expected. I ESTABLISHING A BASIS FOR SELECTION i; Determining which animals are to remain in i breeding herd and which ones are to be sold 7' he key to herd improvement. Differences ng individual animals are caused by differ- ~ in the Way they are fed or treated (their pectively, associate animal husbandman and geneti- ; animal husbandman and geneticist; and superinten- i Substation No. 23, McGregor, Texas. Beef Cattle Performance II. Iekction Based on Gaining Abiliify T. C. CARTWRIGHT, BRUCE L. WARWICK and H. O. HILL* environment) and differences in the individual’s inheritance or genetic makeup. Actually both sets of differences affect all characteristics, but the more important fact to consider in a breed- ing program is that individual animal differences in some characters (characteristics) are produc- ed to a greater extent by inherited differences than is the case with other characters. If differ- ences in a character are due largely to inherited differences, the character is said to be highly her- itable and proper selection can be expected to im- prove the herd average for this character. How- ever, if differences among animals are due almost entirely to environmental differences, selection Will not improve the herd average for this charac- ter. The amount of improvement that can be achieved by selection depends also on how large the differences are among individuals and how ac- curate the selection is in picking the top animals. This is important because of the effect of considering too many characters in selection. Most progress can be made in improving a certain char- acter by considering only that one character. The amount of progress to be expected in improving a single character decreases as the total number of characters considered in selection increases. If noticeable improvement.is to be made, the number of characters must be limited. This point seems to be little understood. It has been said that se- lection for looks or conformation might not help but that it does no harm. It does do harm, as CONTENTS Page Digest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 Establishing a Basis for Selection . . . . 3 Results . . . . . . . . . . . . . . _ . . . . . . . , . . . . . . 4 Recommendations . . . . . . . . . . . . . . . . . . 6 Acknowledgments . . . . . . . . _ . . . . . . . . . 7 Literature Cited , . . . . . . . . . . . . . . . . . . . . 7 Figure 1. Left—This 7- pointed out above, because it greatly reduces the amount of progress possible for more useful pro- duction characters. Determining what characters to consider is important. Only points that have economic value should be considered and those with the most value should be emphasized. The advantages of selecting for characters high in heritability, ex- hibiting large differences among individuals and having high economic value are evident. Tests from five experiment stations show that differences in ability to gain weight are caus- ed largely by differences in inheritance, that is, the character is high in heritability. The work at McGregor reported in Bulletin 790 indicates that heritability of differences in gaining ability is about 50 to 55 percent. This is considered very high, as compared with most quantitative or measurement-type characters, and allows com- paratively rapid improvement under intense se- lection. Differences among individuals are large enough to make selection worthwhile. In the 1953-54 McGregor gain evaluation test, the h i g h - gaining Hereford bull gained 3.1 pounds per day over the 140-day period, while the low-gaining bull on the same feed gained 1.0 pound per day. Such differences form the basis for selection. Gaining ability has high economic value. For beef cattle of about the same age and degree of finish, weight at market time is the most im- portant character. The ability of young beef cat- tle to grow or gain weight is the character that warrants most attention in selection, first, be- cause it is important economically, and, second, because it is highly heritable and there are large differences among animals of the same breed. The economic value of gain can be measured readily in dollars. 4 year-old Hereford cow produced five calves in 5 years. RESULTS Six annual gain evaluation tests have completed, including 453 animals from coope tors and 825 raised at McGregor. The early were for 154 days. The present tests contin n for 140 days after a 2-week adjustment perif All breeding animals have been fed a high roug age or growing ration. Part of the steers - year were fed a high concentrate ration. At cal ration consisted of about 65 percent Johns grass hay and Hegari fodder, 20 percent sorgh i, grain and 15 percent cottonseed meal. All gredients were ground and mixed and self-f without restricting the amount. if The emphasis in selection at McGregor .1 been on growth as indicated by gaining abili However, when the herd was brought together; 1948, few animals with known or tested gain‘ ability were available. Calves from cows bulls raised and tested at McGregor Farm .4 supplying information on the gain of the 5 and the gain of its offspring. This gives an tual measure of the extent gaining ability .01 parent is passed on to its offspring. i Animals fed in different years often,“ differently. Also, animals of different sexes :3 differently. For these reasons, it is necessary evaluate an animal on its ability to gain in r tion to the rate of gain of other animals W were fed the same way, at the same place, du the same period and were of the same breedi sex. This may be done by the use of a “gain tio.” A gain ratio shows how the animal ~j pares with the average for the same breed‘ sex, and makes possible a comparison of 1 y results with those from other years. ~ The gain ratio is computed for each anil by dividing its gain on test by the average 1p on test of animals of the same year, breed,.: Of the four that have been tested, - were high gainers and averaged 24 percent above their gain test average. She has been proved by the performance of offspring. Right-Mr. BF 909, a 13-year-old son of the cow at the left, was 40 percent above average in gain. It is mo? practical to rate an animal's ability by its own performance while it is still young and growing. Such high gainers ma l‘ excellent herd replacements. a bration group and multiplying by 100. Ex- 19S! Hereford bull N0. 3089 gained 373 pounds in the 1953-54 test. All Here- ford bulls gained an average of 343 i pounds in this test. The gain ratio for . 373 ___ No. 3089 1s ma): >< 100 - 112. Hereford bull No. 1047 gained 343 i pounds. w . . . . 343 ___ H1s gain ratio 18-3712; >< 100 -— 100 l, an average animal will have a gain ratio of awhile any animal below average will have a p- ratio below 100, and one above average a , ratio above 100. To be most useful, the gaining abilities o1’ 6 parents should be known. Table 1 gives the lts from all tested offspring (whose sires and y were also tested) through the 1953-54 test. 5 Table 1 illustrates several important things: (1) Heritability appears to be about as first ated. This is the test of the heritability fates. The offspring were above average but j as far above as were their parents. They not expected to be. The parents were 12.0 i ent above average and the offspring were 6.8 ‘ ent above average. Stated differently, the pring inherited 56.7 percent (6.8-—I-12=56.66) . he parents’ superiority in gaining ability. In case, heritability appears to be 56.7 percent, fch is not greatly different from the estimate l» to 55 percent. (2) Not every offspring is above average. a is not expected to be. Each animal has its own individual complex ironment, not all aspects of which are under l‘ Figure 2. Heifers on test at Substation No. 23. Selection on individual gain records is effective with females as iwith bulls. TABLE 1. GAIN RATIOS OF 10 PAIRS OF GAIN-TESTED PARENTS AND THEIR GAIN-TESTED OFFSPRING , _ _ Average of both Offspring's Parent s gam ratio parent; gain Sire Dam gain ratios ratio 125 97 111.0 83 131 117 124.0 129 114 113 113.5 129 126 94 110.0 114 117 99 108.0 86 126 112 119.0 104 117 105 111.0 106 112 106 109.0 117 117 105 111.0 100 114 93 103.5 1Q 112.0 106.8 Average gain ratio of all cattle tested 100.0 Amount that parents were above average 12.0 Amount that offspring were above average 6.8 experimental control. It is impossible to pro- vide a perfectly uniform environment for all ani- mals. This fact makes it possible for individuals to have by chance better or worse than average environments. This can account for some of the amount by which an individual’s value is above or below average. The “average” offspring from selected high-gaining parents was a higher-gain- ing individual than the “average” offspring from all parents, which included those not selected for gain. (3) Some of the offspring have higher gain ratios than the higher parent. This allows selec- tion to continue to improve. There is a limit some- where but it is not in sight yet. The data in Table 1 are valuable but are not based on enough animals to give final ans- wers. The data summarized in Table 2 are based on animals with only one parent tested and include 206 parents and their 476 offspring. All of the calves were raised and tested at McGregor. The untested parents can be assumed to have been about average in gaining ability. well Figure 3. The Hereford steers and heifers on the left were sired by a selected high-gaining bull; the ones on right were by a selected low-gaining bul. There was little difference in the appearance of these two groups but t scales told a real difference. Those from the high-gaining sire gained 14.4 percent more weight during the same perij on the same ration. A These results include all available informa- tion from the herd through the 1953-54 test. N0 offspring were culled until after they were test- ed. The various heritability estimates agree well. Estimates from work in Texas reported prev- iously and considered most valid are 52.9 percent from Balmorhea (Patterson et al., 1955) and 53.8 percent from McGregor (Warwick et al., 1955). If an animal is not tested, it is assumed to be aver- age, regardless of its appearance. Parents not tested have had 444 offspring (including ‘Mc- Gregor-raised calves) gain-tested at McGregor. These calves have an average gain ratio of 98, which is only slightly below the average of all calves tested. RECOMMENDATIONS Throughout Texas, beef cattle producers fol- low various systems of breeding and purchasing replacement cows and bulls. The significant points which fit all systems under which cattle are bred follow: Select under practical production conditions. The breeder should keep in mind that he is breed- ing cattle to be used for beef production, directly or indirectly. Selection should be done under con- ditions similar to those under which the cattle or their offspring will be expected to produce. This would eliminate nurse cows. Creep feeding often is not desirable since this obscures the moth- er’s milking ability which contributes to a calf’s weight for age. Extra feeding and pampering should be avoided. TABLE 2. AVERAGE GAIN RATIOS OF TESTED OFF- SPRING AND THEIR ONE TESTED PARENT Average gain ratio of 206 parents . . . . . . . . . . . . . . . . . . ..l04.9 Average gain ratio of 476 offspring . . . . . . . . . . . . . . . . ..l0l.3 Amount parents were above average . . . . . . . . . . . . . . .. 4.9 Amount offspring were above average . . . . . . . . . . . . .. 1.3 Percent of parent's superiority in gaining ability which 1.3 carried over to offspring H X 100 = 26.5 percent Since only one parent was-tested. heritability is twice the above value . . . . . . . . . . 2 X 26.5 = 53.0 percent Select at a practical age for producti Breeding animals should be selected at the age which the producer sells his slaughter cattle. y mature animal should not be selected on the bass of size or looks. The decision to keep or c“, should be made when the animal is 6 to 18 monti of age-—whenever the commercial cattle are no T mally marketed. Obtain actual weights. Cattle are sold the pound. The breeder should have scales or y’ cess to them to make accurate selections. ' Determine ages of calves. Weight is if portant only in terms of age. It is not sound-l estimate age according to the weight and then 1 lect calves on the basis of weight for age. Bil] dates should be known. Figures should be cf pared for weight per day of age for calves . are not more than 3 or 4 months different in up to weaning. After weaning, similar figuy should be compared for calves whose ages a within 6 months of each other. Compare animals on the basis of rela _, rather than actual gain. Cattle often make ferent gains in different years. Different s‘ gain at different rates. Comparisons of ac pounds of gain should be avoided except for mals of the same sex which were fed together same year. A gain ratio or some similar ran q method is useful. The important thing to con is the animal’s performance in relation to thf others in the same group, regardless of the‘ ber in the group. Relative or actual gains‘ little for comparison purposes if the animals not treated the same. Either feedlot or pa,’ gainis satisfactory since gain either place flects inherent ability. Heavy grain feedin neither necessary nor desirable. L Select on the basis of weight gain. T _ the most important point. It does not whether weight per day of age or gain du f7 test period is used. Select the high gainers cull the low gainers. Select on the individuals gain. record. t cords can be obtained on breeding animals at c _. ‘Long waiting and complicated progeny or pring records are not necessary. An animal ld be selected on the basis of its own gain. -: Worthwhile to get progeny records to back fthe individual’s own record or to test an old ‘that has no record of his own. However, it j 0t practical to wait for long complicated tests. simpler and just as effective to use the in- ldual’s own record. vSelect both sexes. Gaining ability can be fured in bulls and heifers with equal accur- “It is more important to select high-gaining 5'1? and the standards should be higher for bulls. fever, for the 20. to 50 percent of the heifers t normally can be culled from a herd, the slow- rowing, low-gaining ones should be discarded. Keep selection simple and sound. The breed- iltpshould have accurate records. He should use In as the primary consideration in selection. §r1tabihty is probably higher for gaining ability n any other character of economic importance 1 there are great differences among individ- S. l? s Buy tested high-gaining bulls. Commercial Lducers look to the purebred breeders as a grce of bulls. The purchaser should insist on g e evidence that a bull is inherently a good ner so that he will increase his chances of hav- t: faster-gaining calves which will be heavier weaning or later market time. Feeders are 'nning to look for this kind of breeding be- Cd a calf and to pay a premium for it. The ducer looking for a replacement bull should in mind the points listed previously. Some hers are beginning to set up their own tests .t0 have some of their calves tested at PanTech Farms, Panhandle, Texas; Substation No. 9, Bal- morhea, Texas; or Substation No. 23, McGregor, Texas. A permanent listing or registry from the McGregor test for all tested purebred calves is available as a supplement to Bulletin 790.. ACKNOWLEDGMENTS This is a cooperative project with the U. S. Department of Agriculture, and is part of the S-10, Southern Regional Beef Cattle Breeding Project. E. J. Warwick, formerly S-10 coordina- tor for the Southern region, has contributed to this project and given helpful suggestions. Appreciation also is expressed to the follow- ing for their assistance in these experiments: R. E. Patterson, vice director, Texas Agricultural Experiment Station; J. C. Miller, J. K. Riggs and O. D. Butler, head, professor and associate pro- fessor, respectively, Department of Animal Hus- bandry, Texas A&M College System. LITERATURE CITED Patterson, R. E., T. C. Cartwright, J. H. Jones and J. J. Bayles. 1955. Performance testing of beef breed- ing stock. Journal of Animal Science (in press). Warwick, Bruce L. and T. C. Cartwright. 1955. Her- itability of rate of gain in young growing beef cattle. Journal of Animal Science ‘l4z363. Warwick, Bruce L., T. C. Cartwright and M. W. Ha- zen. 1954. Beef cattle performance at Bluebonnet Farm. I. Evaluation tests for gaining ability. Texas Agricul- tural Experiment Station Bulletin 790. Warwick, Bruce L., T. C. Cartwright and Ha- zen. 1954. Supplementary Tables to Texas Agricultural Experiment Station Bulletin 790. Figure 4. Which bull gained nearly twice as much as the other? These two registered Hereford bulls were fed in _ 1954-55 gain evaluation test at McGregor. One made an average daily gain of 3.0 pounds for the l40-day feeding god. The other gained 1.6 pounds per clay. There are large differences among cattle in their ability to gain weight. i, heritability of these differences is high. 7 State-wide Research . ‘k The Texas Agricultural Experiment Station ' is the public agricultural research agency 4 oi the State oi Texas. and is one oi nine ' Location oi field research units in Texas main- tained by the Texas Agricultural Experiment Station and cooperating agencies parts oi the Texas AtS-M College System. IN THE MAIN STATION, with headquarters at College Station, are 16 subject-matter departments, 2 se _ departments, 3 regulatory services and the administrative staff. Located out in the major agricultural . A of Texas are 21 substations and 9 field laboratories. In addition, there are 14 cooperating stations o by other agencies, including the Texas Forest Service, the Game and Fish Commission of Texas, the l Department of Agriculture, University of Texas, Texas Technological College and the King Ranch. S _ experiments are conducted on farms and ranches and in rural homes. RESEARCH BY THE TEXAS STATION is organized by programs and projects. A program of research sents a coordinated effort to solve the many problems relating to a common objective or situation. A’ search project represents the procedures for attacking a specific problem within a program. THE TEXAS STATION is conducting about 550 active research projects, grouped in 25 programs which clude all phases of agriculture in Texas. Among these are: conservation and improvement of soils; I servation and use of water in agriculture; grasses and legumes for pastures, ranges, hay, conservation.’ improvement of soils; grain crops; cotton and other fiber crops; vegetable crops; citrus and other sub i cal fruits, fruits and nuts; oil seed crops—other than cotton; ornamental plants—including turf; Brush: weeds; insects; plant diseases; beef cattle; dairy cattle; sheep and goats; swine; chickens and turkeys; mal diseases and parasites; fish and game on farms and ranches; farm and ranch engineering; farm ranch business; marketing agricultural products; rural home economics; and rural agricultural econ Two additional programs are maintenance and upkeep, and central services. RESEARCH RESULTS are carried to Texas farm and ranch owners and homemakers by specialists and agents of the Texas Agricultural Extension Service.