@ Methods of Sup plymg I Phosphorus to Range Cattle v Q 1n South Texas I . TEXAS AGRICULTURAL EXPERIMENT STATION J R. D. LEWIS. DIRECTOR. COLLEGE STATION. TEXAS DIGEST Extensive areas of sandy soils in South Texas are low in phosphorus. Experiments conducted from 1937 to 1941 showed that the vegetation on these soils was low in phosphorus and that range cattle, especially lactating cows, frequently showed symptoms of phosphorus deficiency. Hand-feeding of phosphorus supplements-bonemeal and disodium phosphate-prevented phosphorus deficiency and corrected already existing deficiencies if they were not too far advanced. Additional work was conducted from 1941 to 1946 to develop more practical methods of supplying phosphorus to cattle, and to determine the effect of applications of different phosphates on the yield and chemical composition of pasture forage. The work was conducted on Nueces fine sand, a typical phosphorus-deficient soil of the region, on the King ranch near Falfurrias. Phosphorus was supplied to the cattle by feeding bonemeal in self-feeders, by adding disodium phosphate to the water supply and by fertilizing pastures with triple superphosphate. All three methods of supplying phosphorus prevented phosphorus deficiency in cattle in normal seasons. Fertilized pasture had a greater carrying capacity than unfertilized pasture. During prolonged drouth, however, the fertilized pasture did not supply enough forage and phosphorus for the cattle at the heavy rate of stocking used. Cows that received phosphorus supplements and cows on pasture fertilized with triple superphos- _f phate produced larger calf crops and heavier calves at weaning time than cows that did not receive‘. phosphorus supplements. The cows that did not receive a phosphorus supplement produced 93 pounds of weaned calves per A acre; cows that were fed bonemeal, 116 pounds; cows that received disodium phosphate in drinking} water, 143 pounds; and cows on fertilized pasture, 176 pounds. The group of cows that did not receive a phosphorus supplement yielded a gross return of $13.91 per acre for the 4 years. After deducting the cost of phosphorus supplements or fertilizer, the cow that were fed bonemeal gave a return of $16.91 per acre; cows that received disodium phosphate water, $20.39; and cows on fertilized pasture, $19.97. " Feeding phosphorus supplements increased the amount of inorganic phosphorus in the an‘ stream of the cattle. - Applications of several different phosphates to pastures increased the yield and phosphorus contend of pasture forage, but had little effect on its protein content. The front cover picture is of the first cross Brahman-Hereford heifers at the start of the experij“ ment, July 30, 1941. I CONTENTS Pag Digest ............................................................................................................................................................................................................... .. _ Introduction ...................................................................................................................................................................................................... .. f Review of Literature ..................................................................................................................................................................................... .. l; Object of the Work ........................................................................................................................................................................................ .. I Vegetation, Soils and Rainfall of the Region .................................................................................................................................. .- Vegetation ............................................................................................................................................................ .. Soils .................................................................................................................................................................................. .. Rainfall ..................................................................................................................................................................................................... Method of Conducting the Work ................................................................................................................................................................. .. Application of Phosphates on Small Plots ...................................................................................................................................... Methods of Supplying Phosphorus to Cattle .................................................................................................................................... -- Experimental Results ..................................................................................................................................................................................... - Yields of Forage ..................................................................................................................................................................................... -. Phosphoric Acid Content of Grasses .................................................................................................................................................. Protein Content of Grasses .................................................................................................................................................................. .- Amount of Available Phosphoric Acid in the Soil .......................................................................................................................... Inorganic Phosphorus in Whole Blood ............................................................................................................................................... .- Phosphorus Intake of COWs in Groups 2 and 3 ................................................................................................................................ -- Weights of Cows and Calves ...................................................................................................................................................... _. Calf Production .................................................................................................................................................................................. --_ Production and Returns ....................................................................................................................................................................... .1- Discussion of Results ................................................................................................................................................................................... -- Summary and Conclusions ......................................................................................................................................................................... Literature Cited ............................................................................................................................................................................................ -- ethods of Supplying Phosphorus to Range Cattle in South Texas E. B. REYNOLDS, J. M. JONES, J. H. JONES, J. F. FUDGE and R. J. KLEBERG, JR.* RESULTS PUBLISHED in this bulletin were periment on methods 0f supply- ge cattle conducted jointly Texas Agricultural Exper- e Bureau of Animal Industry Department of Agriculture 1941 to 1946. The Tennessee Knoxville, Tennessee, furnished ed in pasture fertilization. ined in an ex phosphorus t e King ranch, the F» Station and th .9 he United State 1 Falfurrias from ey Authority, phosphates us , The work consis ication of phosph y the effects of p composition of forage; Jnhorus to range cattle i ly, feeding phosphorus ted of two phases: ates to range land to deter- hosphate on yield and ch and (2) supplying n a controlled water supplements in self- grazing cattle on pasture fertilized Some of the results effects of phosphate ition of range forage as Station P. R. 1341, Range Cattle Through d,” by E. B. Reynolds, s. The results obtained hosphorus to range in USDA Technical s of Supply- by W. H. Black, . Kleberg, Jr. of the experiment sed form in this le to Texas ranch- uperphosphate. ye work to determine the f'eld and chemical compos reported in 1951 in Tex plying Phosphorus to 'lization of Range Lan Fudge and J. M. Jone ethods of supplying p ‘- were published in 1949 “Comparison of Method ihosphorus to Range Cattle,” V; Tash, J. M. Jones and R. J {The results of both phases Ybrought together in revi in so they will be availab ‘fin one publication. REVIEW OF‘ LITERATURE Much research ha horus supplement 'ent soils in variou i t 25 years. fon the subje s been done on feeding s to cattle on phosphorus- s parts of the world during A complete review of the litera- ct is not necesarry in this bul- urvey of the research in Texas g g on phosphorus deficiency is given here. has been known gin the Gulf Coas ‘ent in phosphorus. 'n diseases of cattle for many years that the airie of Texas are It was surmised that might be connected in fway with low phosphorus content of the Actively, professo r and professor, sor, Departme '; and president r, Department of Agronomy; pro- Departmentpf Animal Husban nt of Agronomy, College St , King Ranch, Kingsville, Tex soils in the region (6). Schmidt (7) reported in 1926 that feeding mixtures of bonemeal and salt to range cattle in the region prevented “creeps” (an extreme deficiency of phosphorus, which is also called aphosphorosis) and greatly reduced losses from diseases other than those of an infec- tious character. Cows that were fed bonemeal reared more and better calves than cows that were not fed bonemeal. Stansel, Reynolds and Jones (8), in conduct- ing pasture investigations at the Angleton station in Brazoria county, stated that mature grasses did not contain enough phosphorus for adequate nutrition of range cattle. When harvested at monthly intervals, however, the regrowth of Dallis, Bermuda and Angleton grasses contained enough phosphorus. Fraps, Fudge and Reynolds (4) found that the application of superphosphate to pastures greatly increased the yield and phosphorus content of total pasture forage and of carpet grass. In general, application of superphosphate provided enough phosphorus in the forage for range cattle. Reynolds and Wyche (5) reported that fer- tilizers containing superphosphate more than doubled the yield of forage and increased its phosphoric acid content about 50 percent and its protein content about 20 percent on a heavy black clay soil at Beaumont in the Gulf Coast Prairie from 1936 to 1943. Fraps and Fudge ( 2) showed that many soils in Texas are low in phosphorus. They also found a high correlation between the phosphorus content . 0f grasses and the total phosphorus content of the soils in East Texas (3). Black, Tash, Jones and Kleberg ( 1) made an extensive study from 1937 to 1941 to determine what mineral elements were deficient in the vege- tation of South Texas and methods of correcting such deficiencies. Previous work in South Africa had shown that feeding adequate amounts of bonemeal would prevent phosphorus deficiency in cattle. Feeding bonemeal brought about a re- markable improvement in growth and condition of the cattle. Bonemeal increased the fertility and milk flow, and these in turn produced more and larger calves. It was thought that the results of studies on phosphorus in South Africa might be applicable 3 to large areas in South Texas where the soils also are low in phosphorus (2). For this reason, work was started in 1937 to determine the extent of mineral deficiencies, especially phosphorus defi- ciency, in the vegetation of the region. The work consisted of three main phases: (a) the collection and chemical analysis of samples of the vegeta- tion; (b) the feeding of bonemeal and other phosphorus supplements to range cattle; and (c) the collection and analysis of blood samples from cattle for inorganic phosphorus. Black, Tash, Jones and Kleberg (1) reported that comparatively few of the vegetation samples contained more than 0.13 percent of phosphorus, but most of them contained more than 0.23 percent of calcium. The indication, therefore, is that cattle grazing on such forage would not get sufficient phosphorus to meet their requirements, but that calcium would be ample. The protein and phosphorus contents of most of the species analyzed tended to be the lowest during winter and drouth periods, when there was the least green feed. Considerable differences existed in the composition of different species and in the same species in various localities and on different soils. The effect of rainfall was usually reflected in increased percentages of phosphorus in the months following the heaviest precipitation. These workers found that feeding supple- ments which supplied as much as 6.5 grams of phosphorus 6 days per week to dry cows grazing phosphorus-deficient vegetation prevented phos- phorus deficiency (Figure 1). Phosphorus sup- plements increased the number of calves and the weight of both cows and calves. In lactating cows, the feeding of 13.4 grams of phosphorus daily resulted in somewhat higher phosphorus content of the blood than 6.5 grams. Disodium phosphate and bonemeal had about the same value Figure 1. A “creepy” cow in Group 1, no mineral supplement, February 1946. Creeps, or acute phosphorus deficiency, is characterized by poo-r condition, a stiff, creepy gait and low blood phosphorus. It results among good milking cows pastured on forage deficient in phos- phorus. It may be prevented by supplying phosphorus supplements. 4 as supplements for cattle pastured on phosphorus- l deficient vegetation. OBJECT OF THE WORK In view of the results obtained by Black, Tash, Jones and Kleberg (1), additional work was done to compare different methods of supply- ing phosphorus to range cattle and to determine the effect of applications of phosphates on the chemical composition of range forage. The spe- cific objectives of the work were: (a) to deter- mine the most practical methods of supplying phosphorus to range cattle; and (b) to determine the effect of the application of phosphates on the phosphorus and protein content of range grasses and on the production of calves. Accordingly, the work at the King ranch was p revised and expanded to attain these objectives.‘ The revised work included the feeding of bone- g meal in self-feeders, the addition of disodium phosphate to the water supply and the large-scale application of phosphates to range land. The work also included various rates of application) of different phosphates on small plots to deter- mine their effect on the yield and chemical com position of range forage. VEGETATION, SOILS AND RAINFALL OF THE REGION The southern part of Texas, in which this»; work on phosphorus was conducted, has a gener- ally smooth undulating surface. It supportsa. growth of varying density of grasses, brush, shrubs and some scattered trees. Vegetation That part of the area where this work was conducted was formerly a tall bunch-type grass-T land broken only by small areas of live oak brush: Major grasses were seacoast blustem (Androp yon littoralis), brownseed paspalum (Paspalamaj plicatulum), hairy grama (Boateloaa hirsatafl; thinleaf paspalum (Paspalam setaceam), switch grass (Panicum virgatam), fringeleaf paspalu y (Paspalum ciliatifolium), sandhill grass (Brae iaria ciliatissima) and gulf cordgrass (Sparti spartinae). The important forbs included indi (Indigofera miniata) , milk pea (Galactia texanaé and partridge pea (Cassia fasciculata). The present vegetation is a mesquite gras land savannah, consisting of scattered to dent stands of mesquite (Prosopis chilensis) as a a overstory to the grasses and forbs. Major grass are sandhill grass, three-awn grasses (Aristl $3919.), gulf cordgrass, with only remnants of ti. taller bunch-type grasses, which formerly We prevalent in the area, remaining in the mo favorable situations. The important forbs i clude sunflower (Helianthus 3mm), croton (Cr 1p.) and local stands of milk pea and part- pea. ‘Present forage production generally is highly ‘nal, the major portions of which usually in the spring and fall as a direct result of seasonal rainfall. The grasses deteriorate ‘a following maturity and, when dried, the 'ty and quantity of the forage is appreciably ced. Lactating cows on range not supple- "ted with phosphorus become deficient in iphorus. “ The soils range from dark, heavy, deep, pro- ive clays and clay loams on the more level s to brown soils of medium depth, very 0W loamy soils and light-colored, deep, loose y soils of low productivity on the undulating ces. cThe experiment was conducted on Nueces sand, a loose sand subject to wind erosion, he Encino division of the King ranch in i) s county near Falfurrias. Nueces fine sand l extensive soil in Brooks, Kenedy, Jim Wells §Hidalgo counties. This soil is low in organic f r and plant nutrients, especially phosphorus. 'ous work ( 1) has shown that grasses grow- ‘on this soil are low in phosphorus. 4i. a all §_l;'I‘he‘ climate of the area is mild, and that of uthern part is subtropical and subhumid. Iverage yearly rainfall is about 30 inches in gstern part and gradually decreases west- _ to approximately 20 inches or less in the i e Western part. The region is subject to "1 ent drouths. lData on rainfall at the Encino division of the Aranch during 1941-48 are given in Table 1. icord of monthly rainfall for 1947 was lost, e total for the year was 31 inches. The ige yearly rainfall for the period was 25.58 p, which was 1.43 inches greater than the 41-year average of 24.15 inches. The rainfall, however, varied widely from year to year and from month to month. It ranged from 34.34 inches in 1941 to 16.17 inches in 1945. September had the highest average rainfall, 5.44 inches, for the 7 years and 3.95 inches for 41 years. Novem- ber, December and February had the lowest aver- age rainfall for the 7 years, but January, Febru- ary and March had the lowest average for the 41 years. The amount and distribution of rainfall greatly influenced the yield and chemical compo- sition of pasture forage. METHOD OF CONDUCTING THE WORK The work on supplying phosphorus to range cattle was conducted from 1941 to 1946 on the Encino division, about 25 miles south of Falfurrias and 60 miles southwest of Kingsville. Although that part of the experiment involving cattle was completed in November 1946, the plot work with phosphates to obtain yields of forage was con- tinued through 1948. This experiment included application of phosphates on small plots to determine the effects of phosphates on yield and chemical composition of forage, supplying phosphorus in a controlled water supply, feeding phosphorus supplements in self-feeders and grazing cattle on pasture fertil- ized with triple superphosphate. The cattle, pastures, corrals, scales and labor were furnished by the King ranch. The Tennes- see Valley Authority furnished the triple super- phosphate used for pasture fertilization. The Texas Agricultural Experiment Station and the Bureau of Animal Industry supervised the project and were responsible for the technical phases of the work and the collection of data. Application of Phosphates on Small Plots Triple superphosphate (about 48 percent), calcium metaphosphate and potassium metaphos- Table 1. Monthly and yearly rainfall in inches on the Encino division of the King ranch, 1941-48‘ I I 7-year 41-year I 1941 1942 1948 I 1944 1945 1946 1948 average average. 2.25 1.85 5.25 0.98 1.08 2.08 0.60 2.01 1.20 1.68 1.98 0.21 0.22 0.60 0.00 8.00 1.10 0.91 5.82 0.17 1.18 5.00 2.14 0.81 1.50 2.28 1.09 4.72 0.48 0.17 0.98 2.05 0.89 1.16 1.49 1.92 4.00 1.98 4.08 2.57 1.29 0.46 1.86 2.81 2.98 5.20 2.64 1.28 1.08 0.61 8.82 1.26 2.26 2.92 j 2.65 2.26 0.24 1.20 0.87 0.40 2.85 1.42 2.04 4 0.00 0.68 0.78 7.62 1.91 1.44 1.84 2.08 2.04 2.00 1.40 5.90 4.86 2.10 7 7.75 14.56 5.44 8.95 1 4.02 4.99 1.22 0.96 4.08 2.48 4.48 8.17 2.05 ‘ber 0.45 0.52 8.18 0.60 0.00 0.00 0.00 0.67 1.40 er 2.05 0.09 1.46 0.58 0.54 0.00 0.00 0.67 1.65 ‘1 84.84 18.99 24.80 26.10 16.77 19.58 88.06 25.58“ 24.15 ‘verage of 25.58 inches is for 8 years, 1941-48. ,5, k T s of monthly rainfall for 1947 were lost, but the total rainfall fo-r that year was 31.00 inches. _ urrias, about 25 miles from the experimental area, as reported by the U.S. Weather Bureau. phate were applied on small plots in the spring of 1941; applications were not repeated in subse- quent years. The triple superphosphate was applied at rates of 100, 200, 400 and 800 pounds per acre. The calcium and potassium metaphos- phates were used at rates of 162 and 164 pounds per acre, which supplied the same amount of phosphorus as 200 pounds of triple superphos- phate. These treatments were laid down on plots 50 feet wide and 300 feet long and were replicated three times. All of the phosphates were applied on the surface of the soil with a fertilizer drill. Additional plots Were established in June 1943 on which fused tricalcium phosphate, a new phosphatic material, was compared with triple superphosphate. On these plots, the triple super- phosphate was used at rates of 100, 200 and 400 pounds per acre. The fused phosphate was ap- plied at rates of 178, 356 and 712 pounds per acre, which supplied the same amounts of phosphorus as 100, 200 and 400 pounds of triple superphos- phate, respectively. The plots were not grazed during the period of the experiment. Yields of forage were obtained on all of the plots. Chemical analyses were made to determine the phosphorus and protein contents of the two main species of grasses, Paspalum pli- catulum and Paspalum setaceum. Methods of Supplying Phosphorus to Cattle This part of the experiment was conducted with four groups of cows of Brahman-Hereford breeding. At the outset, 184 heifers, about 20 months old, were divided at random and placed in different pastures. Pasture 1 contained 575 acres; pasture 2, 681 acres; pasture 3, 586 acres; and pasture 4, 684 acres. Groups 1, 2 and 3 averaged 42 head per year and group 4, 58 head. These cattle were handled as follows: Group 1, pasture 1, no mineral supplement. Group 2, pasture 2, had access to bonemeal in self-feeders. - Group 3, pasture 3, received disodium phos- phate in water. From 20 to 27.5 pounds of disodium phosphate, containing 8.74 percent of phosphorus, were added to 1,000 gallons of water. This solution supplied slightly more than 1 gram of phosphorus per gallon. Group 4, pasture 4, area was fertilized in July 1941 with 56.64 tons of 48 percent triple superphosphate. About 77 acres of brushy land could not be covered. The application approxi- mated 90 pounds of phosphoric acid (P205) per acre on 607 acres. Heifers averaging 706 pounds were placed on the pastures in July 1941 and were kept on them continuously until November 1946, when the experiment was discontinued. Pastures 1 and 3 were stocked at the rate of approximately 1 cow to 14 acres; pasture 2, 1 cow to 16 acres; and pasture 4, 1 cow to 12 acres. One Santa Gertrudis bull was used to 20 cows. The individual weights of the cows were taken at monthly intervals from the beginning of the experiment through April 1945 and after that every 3 months. The weights of the cows at weaning time also were obtained after April 5, 1944. The weights of the calves were taken when .- they were weaned at approximately 240 days. i Blood samples were taken at 28-day intervals from 10 representative cows in each group to»; determine the comparative levels of blood phos- phorus. EXPERIMENTAL RESULTS Yields 0f Forage Yields of green forage obtained from the’: superphosphate plots established in 1941 for theT-g 8 years, 1941-48, are given in Table 2. The yields varied greatly from year to year, depending oi» the amount and distribution of rainfall. The highest yields were obtained in 1941 and 1944, which were years of high rainfall (Table 1). Yields were not obtained in 1943. The low yield: of forage in 1945 and 1946 indicated that th fertilized pasture did not provide enough forag and phosphorus for the 62 head of cattle rangin it. This also is reflected in the low blood phoi phorus of the cows on the fertilized pasture i‘ 1945 and 1946, as shown in Table 7. All the plots treated with phosphates L‘ duced decidedly larger average yields of gree forage than the unfertilized plots, Table 2. P10 f that received potassium metaphosphate produc Table 2. Yield per acre in pounds of green forage on fertilized plots, 1941-481 ' Average Treatment per acre 1941” 19423 1944‘ 1945“ 19463 19473 1948‘ Pound 800 lbs. superphosphate 10,620 1,330 5,240 2,790 1,440 2,140 2,180 3,680 400 lbs. superphosphate 10,610 - 1,710 5,410 3,310 1,470 2,790 2,760 4,010 200 lbs. superphosphate 9,080 1,860 4,690 2,280 1,260 2,810 2,790 3,540 100 lbs. superphosphate 9,170 1,870 4,600 2,270 1,280 2,990 2,150 3,480 164 lbs. po-tassium metaphosphate 10,710 1,800 5,290 2,570 1,530 3,450 2,980 4,050 162 lbs. calcium metaphosphate 9,070 2,120 5,100 2,790 1,150 2,910 2,930 3,730 None 6,930 1,120 3,190 1,220 1,040 3,060 1,720 2,610 Average 9,460 1,690 4,790 2,460 1,310 2,880 2,500 ‘Yields not obtained in 1943. °Total of 3 cuttings. “l cutting. ‘Total of two cuttings. 6 Table 3. Yield per acre in pounds of green forage on fused phosphate plots, 1944-48 Average tment per acre 1944 1945 1946 1947 1948 Pounds Percent ; 1ncrease i» fused phosphate 8,180 3,220 1,510 2,340 2,940 3,640 81.1 fused phosphate 7,510 2,370 1,290 2,440 3,060 3,330 65.7 fused phosphate 5,680 2,340 1,140 2,330 2,690 2,840 41.3 . triple superphosphate 7,930 3,140 1,370 2,510 3,600 3,710 84.6 ’ . triple superphosphate 7,100 2,440 1,260 2,120 3,850 3,350 66.7 triple superphosphate 6,460 2,960 1,700 2,870 3,820 3,560 77.1 s, 3,340 960 1,120 2,400 2,250 2,010 verage 6,600 2,490 1,340 2,430 3,170 {a phtly higher average yield than any other ‘a ent used. This possibly indicates that the ium in potassium metaphosphate may have {responsible for part of the increase in yield. treated with calcium metaphosphate pro- VF a little larger yield than plots that received a unds of triple superphosphate. ‘The appli- u of 400 pounds of triple superphosphate per was as effective as that of 800 pounds. ; used tricalcium phosphate, a new phosphatic izer, became available in 1943. A new series a was established that year to compare this ‘rial with triple superphosphate. The fused hate was applied at rates of 178, 356 and :,p0unds per acre, which supplied the same nts of phosphorus as 100, 200 and 400 ids of triple superphosphate, respectively. yields of green forage obtained from these from 1944 through 1948 are given in Table 5 he treatment of 400 pounds of triple super- fhate made a slightly higher average yield § any other treatment. The phosphate treat- ; increased the average yields of forage 41.3 * y, .6 percent above the yield of the unfertilized Triple superphosphate produced about 8 nt more forage than the fused phosphate. results indicate that there was very little f ence in the effectiveness of triple super- lhate and fused phosphate. Phosphoric Acid Content of Grasses The phosphoric acid content of the air-dry forage of the two main species of grasses, Pas- palum plicatulum and Paspalum setaceum, was determined on samples collected when yields of forage were obtained. The phosphoric acid con- tent of both grasses varied considerably from year to year. Apparently, the phosphoric acid content was associated with rainfall. It tended to be high in new growth and during periods of favorable rainfall, and low in Winter and during periods of drouth. As an average for the 7 years, the grasses on the plots that received phosphate contained from one and one-half to nearly three times as much phosphoric acid as the grasses from the plots which did not receive phosphorus, Table 4. In general, the phosphoric acid content of the grasses increased as the rate of application of t rip l e superphosphate was increased. The heavier applications, 200, 400 and 800 pounds per acre, maintained the average phosphoric acid content at 0.33 percent or above, Which usually is considered adequate for range cattle. Accord- ing to this standard, the two grasses on the plots that received 400 or 800 pounds of triple super- phosphate per acre contained enough phosphorus for range cattle at all dates of sampling, except t 4. Percentage of phosphoric acid (P205) in Paspalum plicatulum and Paspalum setaceum on fertilized plots, 1941-47 1941 1942 1943 1944 1945 1946 1947 ‘vTreatment per acre June Sept. July Dec. Oct. June Oct. Sept. Nov. June Oct. Sept. Av. " 20 5 27 28 22 22 22 20 14 25 3 24 . V, Paspalum plicatulum - is. triple superphosphate 0.83 0.38 0.67 0.50 1 0.71 0.54 0.52 0.48 0.51 0.58 0.40 0.55 triple superphosphate .58 .30 .41 .32 .51 .39 .36 .35 .47 .46 .38 .41 _; a: triple superphosphate .54 .30 .33 .37 .52 .25 .36 .18 .37 .46 .19 .35 p. . triple superphosphate .43 .23 .28 .28 .40 .28 .31 .24 .33 .38 .26 .31 l; potassium metaphosphate .52 .29 .29 .25 .28 .20 .32 .17 .33 .39 .32 .31 calcium metaphosphate .42 .24 .26 .20 .27 .25 .33 .23 .34 .42 .27 .28 .22 .19 .17 .13 .21 .17 .27 .18 .25 .29 .21 .21 . Paspalum setaceum triple superphosphate .83 1 .58 .74 .51 .7 4 .48 .63 .42 .73 .49 .53 .61 l. triple superphosphate .58 .54 .54 .48‘ .58 .42 .47 .33 .55 .52 .44 .50 l». triple superphosphate .54 .34 .40 .42 .43 .34 .43 .25 .46 .42 .43 .41 triple superphosphate .43 .44 .40 .43 .36 .30 .36 .24 .33 .44 .31 .37 ~ potassium metaphosphate .61 .39 .38 .43 .29 .29 .36 .27 .38 .42 .41 .38 calcium metaphosphate .47 .32 .37 .44 .32 .30 .36 .17 .33 .39 .31 .34 A .27 .15 .25 .24 .16 .15 .23 .15 .21 .36 .21 .22 sis of this species not obtained on this date. September 5, 1941. The grasses from the unfer- tilized plots contained, on the average, only 0.21 percent of phosphoric acid. Protein Content of Grasses Apparently the application of different phos- phates had no appreciable effect on the protein content of Paspalum plicatulum and Paspalum setaceum, as shown in Table 5. The protein con- tent, however, varied widely in different seasons. It ranged from about 12 percent in September 1945 to 4 percent or below in October 1944. The protein content appeared to be associated with stage of growth and amount of rainfall. In gen- eral, a high protein content followed periods of favorable rainfall. There was not much differ- Ience in the average protein content of the two grasses. Amount of Available Phosphoric Acid in the Soil The amount of available phosphoric acid was determined in the soil on the areas involved in the work, including the small plots and the large fertilized and unfertilized pastures, in 1945 and 1947. The application of phosphates greatly in- creased the amount of available phosphoric acid in the soil, as shown in Table 6. For example, in 1945 the soil that received 800 pounds of triple superphosphate per acre contained 27 parts per million of available phosphoric acid (equal to 54 pounds per acre) in the surface soil, and the un- treated soil contained 4 parts per million. In general, the amount of available phosphoric acid in the soil increased as the rate of application of phosphate was increased. Soil treated with calcium and potassium metaphosphates contained about as much avail- able phosphoric acid as soil treated with equal amounts of phosphoric acid in triple superphos- phate. Table 6. Amount of phosphoric acid (P205) in parts Q million of surface soil at various places, 19, and. 1947 . Treatment per acre 1945 1947» Super-phosphate plots (established in 1941) 800 lbs. triple superphosphate 27 21 .- 400 lbs. triple superphosphate 14 6 I 200 lbs. triple superphosphate 11 4 v 100 lbs. triple superphosphate 7 5 . 164 lbs. potassium metaphosphatel 10 5 162 lbs. calcium metaphosphate‘ 10 4 ; None 4 3 ‘ Fused phosphate plots (established in 1943) 400 lbs. triple superphosphate 16 7 t 200 lbs. triple superphosphate 9 4 100 lbs. triple superphosphate 6 4 712 lbs. fused phosphate2 25 15 E 356 lbs. fused phosphatez 19 8‘; 178 lbs. fused phosphatei 6 4 None 5 3; Large pastures 200 lbs. superphosphate, pasture 4 6 None—Pasture 1 4 Pasture 2 3. Pasture 3 2, 200 lbs. triple superphosphate, Vivoras pasture - None, Vivoras pasture ‘These amounts of potassium and calcium metaphosph supply the same amounts. of P205 as 200 pounds of tri superphosphate. ‘ "The 178, 356 and 712 pounds of fused phosphate con the same amounts of P205 as 100, 200 and 400 pounds triple superphosphate, respectively. Table 6 shows that the amount of availat phosphoric acid in the fertilized soil was w; siderably less in 1947 than in 1945, which in cates that it was being depleted to the level available phosphoric acid in the untreated s Inorganic Phosphorus in Whole Blood Samples of blood were collected from I representative cows in each group at mont intervals from August 1941 to November "' Table 5. Percentage of protein in Paspalum plicatulum and Paspalum setaceum on fertilized plots, 1941-47 1941 1942 1943 1944 1945 1946 1947 Treatment per acre June July Dec. Oct. June Oct. Sept. I Nov. June I Oct. Sept. Ave 20 27 28 22 22 22 20 I 14 25 I 3 24 ' Paspalum plicatulum 800 lbs. triple superphosphate 7.45 5.67 5.20 1 6.42 4.50 11.35 4.50 9.54 6.75 3.55 400 lbs. triple superphosphate 7.84 6.15 4.70 5.13 3.85 10.00 4.74 11.17 8.02 3.70 200 lbs. triple superphosphate 7.49 6.15 5.11 5.74 3.80 10.55 5.28 9.85 6.55 3.45 100 lbs. triple superphosphate 7.54 5.73 5.16 6.74 5.00 9.48 5.85 9.66 6.50 3.60 164 lbs. potassium metaphosphate 6.74 5.47 5.30 5.05 3.81 10.70 5.70 9.90 7.11 4.05 162 lbs. calcium metaphosphate 7.09 5.38 4.54 ' 4.80 5.29 11.70 5.90 9.88 8.65 3.70 None 8.35 5.67 4.93 5.32 3.90 9.80 6.70 10.50 8.48 5.00 Paspalum setaceum 800 lbs. triple superphosphate 7.38 5 43 6.87 6.05 6.54 3.90 11.48 4.21 8.69 6.10 4.50 400 lbs. triple superphosphate 6.55 5 69 6.55 5.73 6.13 3.70 10.28 4.37 8.87 6.50 3.70 200 lbs. triple superphosphate 5.70 5.54 6.41 5.95 5.55 4.58 11.25 4.36 9.14 6.88 4.30 100 lbs. triple superphosphate 6.12 5.82 6.55 5.90 5.74 4.30 10.78 4.01 9.80 6.52 4.30 164 lbs. potassium metaphosphate 5.97 5 75 6.27 6.40 4.55 4.75 11.38 4.72 9.36 7.35 4.22 162 lbs. calcium metaphosphate 5.62 5 25 6.49 6.01 4.95 4.86 12.28 4.53 8.87 7.20 3.72 None 6.88 5 73 6.37 7.05 4.27 4.20 10.58 6.00 8.50 8.15 4.40 "$3 91-155»: ||»1|He_.{_.._..l...‘ I ‘Analysis of this species not obtained on this date. 8 _ determination of inorganic phosphorus. ' ounts of phosphorus in these samples, ex- ” as milligrams (mg) per 100 cc of whole jare given in Table 7. e average phosphorus content of the blood cows of each group was about 4 mg or in 1941 and 1942. Since this level of orus was found in young cattle making k tory development, it is assumed that such Zindicate adequate phosphorus nutrition. ; ere was a sharp decline in the blood phos- i in all groups soon after calving began in ’ber 1942. The blood phosphorus of the - group 1, which were not fed a phosphorus pment, continued to drop until August 1943, p general, was lower than that of groups ed 4 during the remainder of the experiment. (‘ms of creeps, or phosphorus deficiency, ommon in lactating cows in group 1. The Vel of blood phosphorus and symptoms of q orus deficiency indicated that the cows did " eive adequate phosphorus nutrition. The ~e provided adequate nutrition for the devel- "it of heifers but did not permit an adequate if phosphorus for lactation. The blood phosphorus content of the cows in group 4, on the fertilized pasture, was higher than that of the cows in group 1, except in the winter of 1945 and 1946. The cows in this group did not show symptoms of phosphorus deficiency ex- cept in the drouth of 1945 and in the winter of 1945-46. The cows in group 4 had 55 calves in 1946 and the cows in group 1 had only 10. The stocking rates for groups 1 and 4 and the dry summer of 1945 greatly reduced the amount of pasturage and consequently the amount of phos- phorus available. This may account for symptoms of creeps in these groups; however, the conditions were more severe in group 1 than in group 4, as shown by the number of calves in the latter group. Group 3, which received disodium phosphate in water, maintained a high level of blood phos- phorus and did not show evidence of creeps. After 1942, except from November 1943 to May 1944, the blood phosphorus of this group was higher than in any other group. In that period, pond water following rains was available to the cows. The greatest difference for group 3 was the high level of blood phosphorus in June, July, August and September. This is a period in which Table 7. Milligrams of inorganic phosphorus per 100 cc. of whole blood by months and years I I I I I 1941 1942 l 1943 i 1944 | 1945 | 1946 Av} 1941 1942 I 1943 i 1944 1945 1946 Av.‘ I . Group 1. No phosphorus supplement Group 2. Bonemeal self-fed 4.2 4.6 2.7 3.4 2.9 4.6 3.64 4.1 4.5 4.1 4.5 4.7 4.1 4.38 " 5.2 4.3 3.8 4.3 3.4 4.2 4.00 5.2 5.1 3.8 5.0 4.4 4.3 4.52 4.8 4.4 2.8 3.0 3.2 3 6 3.40 4.5 4.2 4.5 4.5 5.1 4.8 4.62 3.7 3.6 3.2 2.8 2.1 — 2.92 3.4 3.9 5.0 5.3 3.1 — 4.32 — 3.9 3.3 3.5 2.8 3.0 3.30 — 4.4 4.1 4.1 4.4 3.9 4.18 — 4.0 3.2 3.7 3.8 2.2 3.38 — 4.8 3.2 4.5 4.2 4.1 4.16 — 4.13 3.17 3.45 3.0 3.52 3.44 4.48 4.12 4 65 4.32 4.24 4.36 — 3.7 2.6 3.0 3.7 2.9 3.18 —- 3.9 2.8 3.1 4.5 3.4 3.54 — 3.8 3.0 3.0 3.0 2.5 3.06 — 4.1 3.6 4.1 5.0 3.9 4.14 — 4.2 2.9 2.8 3.6 3.0 3.30 — 4.3 3.8 4.3 4.9 5.6 4.58 — 3.9 2.8 2.6 2.8 3.8 3.18 — 4.6 3.9 4.2 4.6 4.5 4.36 —- 4.4 2.6 2.1 2.8 2.6 2.90 -— 4.6 4.0 3.8 5.0 3.4 4.16 3.8 3.9 2.3 2.6 2.6 2.5 2.78 4.1 4.6 3.5 4.3 4.7 4.8 4.38 3.98 2.70 2.68 3.08 2.88 3.06 4.35 3.60 3.97 4.78 4.27 4.19 0s. 4.06 2.93 3.07 3.06 3.17 3.25 4.42 3.86 4.31 4.55 4.25 4.28 {Group 3. Disodium phosphate supplied in water Group 4. Pasture fertilized with superphosphate " 4.3 4.3 4.2 4.5 6.0 5.5 4.90 5.2 5.2 4 9 5.8 3.9 5.2 5.00 5.0 5.2 4.5 5.8 4.7 4.1 4.86 5.6 5.1 5 2 5.0 5.1 4.4 4.96 4.9 5.0 4.0 4.8 5.1 5.0 4.78 5.9 4.8 4 5 4.1 4.1 4.1 4.32 3 6 5.0 3.8 5.0 4.7 — 4.62 4 3 4.7 4 1 3.6 2.4 — 3.70 — 4.4 3.4 3.5 4.6 4.6 4.10 —— 4.6 3 7 5.0 3.7 2.3 3.86 — 4.0 4.1 4.4 4.8 4.1 4.28 — 4.7 3 8 4.6 4.0 2.3 3.88 4.65 4.00 4.67 4.98 4.66 4.59 — 4.85 4 37 4.68 3.87 3.66 4.29 — 4.0 4.1 2.5 4.1 3.9 3.72 — 4.3 4.1 4.1 4.3 2.7 3.90 — 4.3 3.7 3.4 5.2 5.1 4.34 — 4.9 4.1 4.6 4.3 2.3 4.04 — 4.8 3.7 4.4 5.7 5.4 4.80 — 5.3 4.4 4.0 4.1 3.1 4.18 — 4.0 5.1 4.8 5.7 4.9 4.90 — 4.8 4.6 3.7 3.7 3.7 4.10 — 4.8 5.5 5.6 6.9 4.8 5.52 — 5.3 3.7 3.0 3.6 3.0 3.72 4.4 5.4 4.9 5.1 6.2 6.2 5.56 4.3 5.1 3.5 3.6 2.7 3.7 3.52 4.55 4.50 4.30 5.63 5.05 4.81 4.95 4.07 3.83 3.78 3.08 3.91 Lmos. 4.60 4.25 4.48 5.31 4.87 4.70 4.90 4.22 4.26 3.82 3.35 4.10 lts not included in averages. the calves made heavy demands on the cows, when seasonal lows in phosphorus content of vegetation may occur and when the consumption of water is increased by hot weather. With phosphorus in- take proportional to the amount of water con- sumed, it follows that the blood level should be high. The lowest average values for blood phos- phorus were found in December, January, Feb- ruary and March, a period in which cooler weather decreased the consumption of water. Group 2, fed bonemeal, had a stable and rela- tively safe level of blood phosphorus throughout the experiment. In a few instances, cows with calves apparently did not consume enough bone- meal to meet minimum phosphorus requirements and showed evidence of “creeps.” The average blood phosphorus level in this group was not as high as that for group 3, particularly in the summer. The differences were not as great dur- ing the winter, and both groups showed (Figure 3) their lowest blood phosphorus levels in March. The greatest variation in monthly blood phosphorus levels was noted in group 3 and the least in group 2. There was slightly more varia- tion in group 1 than in group 2 and almost as much in group 4 as in group 3. The limited variation in group 2 indicates that the cows tended to balance the consumption of bonemeal with the seasonal supply of phosphorus in the vegetation. Greater variation in group 3 is be- lieved to have resulted from differences in water consumption and the use of a constant percentage of phosphate in water. Group 1 had less chance Figure 2. Group 1 cows, no mineral supplement, February 1946. The cows averaged 882 pounds in December 1 Only about 50 percent of the cows dropped calves in 1946, and many of the calves were late. l0 to show variation because of the limited pho phorus supply. Most of the calves were droppi ahead of the time of most abundant pasturag thus, the demand on the cows tended to coincid with feed and phosphorus supply. The variatio, in group 4 seemed to reflect the phosphorus co tent of the vegetation as influenced by availabl moisture. § Table 7 shows that cows which receiv phosphorus supplements had more inorganic phosphorus in their blood than cows which dip not receive the supplements, and indicates th phosphorus may be supplied satisfactorily throu; self-feeders, in a controlled water supply an through pasture fertilization. Supplying pho phorus in self-feeders and in a controlled Wat system maintained a higher level of blood i! phorus than pasture fertilization, but pastu fertilization maintained an adequate level exce during drouth. Phosphorus Intake of Cows in Groups 2 and 3 Cows in group 2 were fed bonemeal in se feeders and cows in group 3 were supplied di " dium phosphate in a controlled water supply. T _ i average daily consumption of phosphorus ' grams per cow by 28-day periods from July 1941 to November 12, 1946, is shown in Table The phosphorus supplements consumed by it calves were charged to the cows. ~ The disodium phosphate contained 8.74 pet cent of phosphorus and the bonemeal 10 perce Fill llfmllwb-H-H-Ai-smm iFigure 3. Group 2 cows, fed bonemeal, in February 1946. The cows averaged 1,140 pounds in December 1945. Most pithe cows were in good flesh and several calves had been dropped although few are shown. lm July 30, 1941 to July 29, 1942, 20 pounds increased to more than 8.0 grams in 1945 and to ¢disodium phosphate were used per 1,000 gallons 12.0 grams in 1946. After 1941, much larger Water. The amount was increased to 27.5 amounts of bonemeal were consumed from March §nds from the latter date to June 2, 1943, re- to September than from September to March. ed to 20 pounds until April 5, 1944 and in- The demand of the calves, or lactation, is a factor sed to 27.5 pounds for the remainder of the affecting the consumption of bonemeal. Appar- riment. . ently, the cows eat bonemeal in an effort to main- tain body reserves of phosphorus and not because Group 2 consumed small amounts of bone- it is palatabla until after the start of calving in December Consumption averaged 6.0 grams of phos- Phosphorus consumed by group 3 followed lirus daily per head in 1943 and 1944, but the same trend as that of group 2, but at a higher i‘ Table 8. Grams phosphorus intake daily per cow by 28-day periods, 1941-46 1 1 1 1 1 1 1 1 1 1 1 1 19411 1 1942 1943 1944 1 1945 1 1946 1 Av.‘ 1941 1 1942 i 1943 1 1944 1 1945 1 1946 1 Av.‘ . 1 1 1 1 1 1 1 1 1 1 1 _v Group 2. Bonemeal in self-feeders Group 3. Disodium phosphate in water _;-9/24 .63 2.19 7.16 5.01 6.36 7.23 5.70 2.37 9.23 7.73 7.36 11.30 7.73 3.33 . 10/22 .63 3.62 4.12 3.09 2.71 6.52 4.01 2.34 6.03 2.06 6.21 6.23 2.36 4.63 11/19 2.33 1.36 5.66 5.31 7.54 3.10 5.69 2.01 4.65 3.37 7.24 3.56 4.03 5.57 412/17 2.33 4.30 3.24 6.90 9.46 -_ 5.93 1.73 7.73 1.96 5.53 7.04 -- 5.53 ‘ ,-1/14 3.77 3.33 4.94 7.99 11.39 _- 7.05 1.12 4.52 1.33 6.54 6.34 -- 4.70 21/11 -- 3.77 3.54 3.31 6.37 9.99 5.50 —- 1.05 3.69 2.37 5.31 5.39 3.76 ,3/11 -- 1.33 3.20 1.23 .75 3.13 3.06 -- 3.39 6.32 3.24 5.12 7.72 5.26 p ge 3.00 4.55 4.34 6.44 3.01 5.23 5.24 3.36 5.64 7.27 5.56 5.49 0-4/8 _- 1.33 5.13 3.77 7.92 15.15 6.77 - 3.39 7.35 2.53 6.61 11.17 6.21 - 3.77 5.99 10.33 7.16 15.33 3.63 -_ 4.12 11.33 9.51 3.90 12.60 9.40 /3 1 7.54 3.36 9.16 11.50 31.44 13.70 - 5.11 13.39 10.36 14.19 10.73 10.37 ‘ ./1 - 3.77 5.66 7.95 3.36 11.37 7.62 —_ 5.97 13.36 12.75 15.96 7.17 11.04 ./29 -—- 3.77 7.92 5.54 15.72 9.99 3.59 i 6.03 15.25 16.13 15.26 13.54 13.24 1 /26 .63 5.99 10.56 3.97 10.35 7.79 3.33 2.57 11.20 12.32 16.26 15.64 11.75 13.53 age 4.45 7.35 7.63 10.34 15.34 9.02 5.97 12.34 11.34 12.76 a 11.17 10.72 3 periods 3.67 5.34 6.13 3.24 12.01 7.01 5.57 7.77 3.27 9.30 3.62 7.90 , results not included in averages. 11 level. There was less variation in phosphorus intake by periods for group 2 than for group 3. Group 3 showed a much higher intake than group 2 in the summer but not in the winter. The trend in intake was upward by years and was much greater from March to September than from September to March. High intake in summer, or during the approximate period of greatest need, appears to be one advantage of supplying phos- phorus in water. Both groups of cows showed higher intakes of phosphorus than the 6.5 grams daily per head which was used as a standard at the beginning of the experiment. The results indicate that, in addition to the phosphorus received from the feeds, 7 to 8 grams should be supplied during periods of low demand imposed by the calves and 14 to 16 grams in periods of high demand, the latter occurring in the spring and summer. It has been observed that cattle prefer a phosphated water supply and that they are able to find such supply just as they are able to find phosphated areas in pastures. Weights of Cows and Calves The average initial and succeeding weights of cows and calves are shown in Table 9. The months in which the calves were dropped and the numbers of cows and calves by years are shown in Table 10. The cows began calving in December 1942 and the calves were weaned at approximately 240 days of age. The average weight of 706 pounds for the heifers at the beginning of the experiment, July 30, 1941, and the average weight of 1,089 pounds, November 18, 1942, indicate excellent growth and condition just before the start of calving. On November 17, 1943, group 1, which did not receive supplemental phosphorus, showed an average weight loss of 161 pounds per head from the year before. Group 2, fed bonemeal, and group 4, on the fertilized pasture, had minor losses of 58 and 38 pounds per head, respectively. Group Table 9. Average we-ights in pounds per head of cows a ~ weaning weights of calves by years Group 3, l , miiiifihia... ‘iiiiiii’ 533331.115, ‘$2235.:- Time supplement bonemeal in Water fertlhzed V, l Cows l Calves Cows I Calves Cows I Calves Cows I Calv 7/30/411 706 708 708 705 11/18/422 1077 1087 1050 1142 11/17/433 916 1029 1051 1106 5 12/13/44 867 1107' 1103 1160 12/12/45 882 1140 1155 1107 11/12/46 1047 1148 1195 1109 I, 1943‘ 774 500 939 524 956 529 993 1944 825 500 1043 516 1028 533 1052 56 1945 789 460 1015 545 1039 519 1007 55, 1946 878 497 1048 556 1099 590 1007 54 Average 802 489 1011 535 1029 542 1015 55, ‘Initial weight. I‘ gWeight before start of first calving in December 1942. 3Weight of cows in late fall. “Weight of cows and calves when calves were weaned. 3, which received disodium phosphate in wat did not lose weight. At the succeeding fall weighings in 19 1945 and 1946, cows in groups 2, 3 and 4 very few calves at side. parable with groups 2, 3 and 4 in this resp after the first year because of later calving a a lower percentage calf crop. The marked 7 crease in weight for group 1 in 1946 resul because less than half the group raised calv Groups 2 and 3 showed small, but steady increa in weight from 1943 to 1946. Group 4 weig l the same in 1946 as in 1943, but showed a g1 from 1943 to 1944. The average weights of c0 in groups 2, 3 and 4 indicate cows of good sip but the effect of drouth and a decreased sup- of phosphorus is indicated for group 4 in '9 and 1946. a The average birth date of calves from gro y 2, 3 and 4 was February 1 and the averages the respective groups varied only from Janu“ 18 to February 25. The average birth date i group 1 calves was March 26 and the range from January 23 in 1943 to May 16 in 1946. i ~. Figure 4. Group 3 cows, fed disodium phosphate in water, February 1946. The cows averaged 1,155 poun December 1945. The cows were strong and in good flesh. Numerous young calves of the 1946 crop are at side. 2 12 l» >- Group 1 was not c0, ' V,_;.-.?.-.?: '- gure 5. Group 4 cows, on pasture f ‘fl‘_l‘he weights 0f cows just before calving be near the greatest of the year and at ling about the least. Group 1 showed a loss pounds per head from November 1942 to ate calves were weaned in 1943. Only 142 s of this loss were regained by November i Groups 2 and 4 showed nominal losses of b 150 pounds, most of which was regained in riod between weaning and calving. Groups 3 Weighed about 200 pounds more per head gtigroup 1 from 1943 to 1946. Group 4 had _f?an advantage except in 1946, when group 1 {ged only 125 pounds lighter. ertilized with superphosphate, February 1946. The cows averaged mber 1945. Note the large number of young calves and that the cows are big, although some are thin. . g: 4155365 l for 1,107 _ ,,:-:~:1:I:4:-. . . :55: . . A high potential of production is indicated the experimental area under favorable condi- tions, since the first calves of group 1 averaged 500 pounds per head when weaned at 240 days. Although the cows in group 1 lost weight in raising the calves dropped in 1943, their calves dropped in 1944 also averaged 500 pounds at weaning. In 1945, the calves averaged 460 pounds, but the summer was dry and many of them were late. Weaning weights were consist- ently above 500 pounds for groups 2, 3 and 4 and tended to increase. The calves in group 3 had an average weight of 590 pounds in 1946. Table 10. Months in Which calves were dropped and numbers of cows and calves» by ye-ars Number % Average Number of calves dropped of calf calving ___ ,5 cows crop date Dec. f Jan. | Feb. | Mar. | Apr. I May I June [July l Aug. | Sept. I Oct. I Nov. I Total Group 1. No phosphorus supplement 11,3 43 90.7 1/23/43 6 27 3 — 2 - 1 —— — — — -— 39 42 90.5 3/17/44 1 5 8 12 8 — 1 1 1 — — 1 38 _ 42 76.2 4/14/45 1 — 1 2 18 4 3 — — 1 — 2 32 40 48.0 5/16/46 1 2 1 1 — 1 5 2 3 1 2 — 19 r _ e 41.8 76.4 3/26 9 34 13 15 28 5 10 3 4 2 2 3 128 Group 2. Bonemeal self-fed 43 93.0 2/3/43 3 20 9 6 2 — — — — — — — 4O 43 93.0 2/25/44 1 7 17 11 3 — — — 1 — — — 40 . A 43 95.3 2/17/45 3 19 9 2 3 — —- 2 2 —— — 1 41 6 40 92.5 1/27/46 12 18 1 2 1 — — — 1 2 — — 37 ‘r ge 42.2 93.4 2/10 19 64 36 21 9 — — 2 4 2 —— 1 158 ‘ i Group 3. Disodium phosphate supplied in water 42 102.4 1/22/43 6 30 3 — — 2 — 1 — — -- 1 43 42 102.4 2/2/44 11 18 2 4 1 2 —+ 1 — 1 — 3 43 42 97.6 1/29/45 18 5 1 7 2 1 2 — 1 — — 4 41 40 92.5 1/30/46 19 5 4 3 — 3 — 1 — — 2 — 37 .,r 4' e 41.5 98.7 1/28 54 58 1O 14 3 8 2 3 1 1 2 8 164 l Group 4. Pasture fertilized with triple superphosphate 62 101.6 1/20/43 10 41 3 3 3 — — 1 — — — 2 63 57 107.0 1/24/44 22 17 4 5 1 5 — 1 — — 2 4 61 57 115.8 1/18/45 25 9 4 1 3 4 — 1 1 — 2 16 66 57 91.2 2/23/46 19 9 4 2 2 2 — 1 — 2 6 5 52 103.9 1/29 76 76 15 11 9 11 — 4 1 2 10 27 242 l ge 58.2 13 Calves in group 4 were uniform in Weight each year. Seasonal influences on production were much the same for groups 2, 3 and 4 because of the rather uniform calving and weaning dates. Calf Production All of the fourth crop of calves and some of the fifth crop had been dropped in groups 2, 3 and 4 by November 1946. Few of the cows in group 1 dropped a fourth calf. The number of calves dropped by months, average date of calving and percentage of calves dropped per cow in the four 12-month periods are shown in Table 10. Some cows in groups 2, 3 and 4 dropped calves in less than 12 months. On the basis of one calf per cow in 12 months as a 100 percent calf crop, group 4 exceeded 100 percent in the first 12-month periods and averaged 103.9 percent for the four periods. Group 3 averaged 98.7 percent for the four periods; group 2, 93.4 per- cent; and group 1, 76.4 percent. The cows in groups 2, 3 and 4 rebred and settled with calf much more readily than those in group 1. Cows in group 1 tended to miss calving and calved later in the year. Cows in group 2 main- tained regular calving, with only 10 out of 161 calves in the four periods being dropped later than May. Group 3 had a scattering of calves through the different months, but most of the cows had calves in December and January. The shift of calving from January to December was definite in the last 2 years. The cows in group 4 also dropped calves from May through September, but there was a definite increase in the earliness of the calves. In this group, fall calves began r appear in the third and fourth years and com posed 25 percent of the calves dropped. Production and Returns The comparative production and costs supplements for the four groups of cows fron‘ July 30, 1941 to November 12, 1946, are sum-P marized in Table 11. The costs and returns are based on the average number of cows in the v groups during the 4 years of production. Forty»; of the 43 cows originally placed in groups 1, 2 and 3, and 57 of the 62 cows in group 4 completed the experiment. ' The number of calves weaned and on which]; returns were calculated differed from the number‘ dropped. While a few calves died, most of th difference was due to late calving in 1946. Calv’ dropped after June 1 were not considered in t‘ ‘ returns. The cows that were lost in the expe ment were replaced to maintain the original stoc ing rates, but their calves were not used in co q puting the returns. ' The four groups started at the same weig in July 1941 and all made satisfactory growth _ to calving, which began in December 1942. T respective average weights in late fall were 1,0 ; 1,087, 1,050 and 1,142 pounds. At subsequ' weighings, cows in group 1 were approxima 200 pounds lighter than the others. The cows A group 3 were the heaviest at the close of t experiment, with an average weight of 1,1 pounds. Groups 2 and 4 followed with avera weights of 1,148 pounds and 1,109 pounds p head, respectively. However, the weights of t Table 11. Summary of production, costs and returns, 1941-46 Group 3, Group 4, past Item no §ll3s1gh1orus b<€122l11§a:1z'in disodium flelfilifed I Supplement self-feeders phosphate Wlth tmple a '2 1n water superphesph Acres in pastures 575 681 586 684 . Average number of cows 41.8 42.2 41.5 58.2 ' Acres per cow 13.8 16.1 14.1 11.8 i Initial weight as heifers July 30, 1941, lbs. 706 708 708 705 r Final weight before calving, Nov., 1942, lbs. 1,077 1,087 1,050 1,142 Average fall weight, 1943-46, lbs. 928 1,106 1,126 1,121 Final weight Nov. 12, 1946, lbs. 1,047 1,148 1,195 1,109 Average weight at weaning time, 1943-46, lbs. 802 1,011 1,029 1,015 Number of calves dropped 128 158 164 242 Number of calves weaned 109 148 154 219 Weight of calves at weaning time, lbs. 489 535 542 551 , Value of weaned calf at $15 per 100 lbs. $73.35 $80.25 $81.30 $82.65 Total weight of calves weaned in 4 years, lbs. 53,340 79,166 83,516 120,704 Total calf weight weaned per cow, lbs. 1,276 1,876 2,012 2,074 Total calf weight weaned per acre, lbs. 93 116 143 176 1 Total phosphorus supplement or fertilizer, tons —- 6.02 7.73 56.64 Cost of supplement or fertilizer per cow‘ — $8.56 $13.97 $76.37 Cost of supplement or fertilizer per acre —- $0.53 $ 0.99 $ 6.5 Total returns per group, calves at $15 per 100 lbs. $8,001.00 $11,874.40 $12,527.40 $18.105. I Return per cow less cost of supplement or fertilizer $191.41 $272.84 $287.89 $234.7 4 Return per acre less cost of supplement or fertilizer $13.91 $16.91 $20.39 $19. ; ‘Prices per ton: bo-nemeal, $60; disodium phosphate, $75; and triple superphosphate, $62.40, plus $1.50 per acre for app l tion on 607 acres. 14 ‘d pasture rent are not considered in the of production given in Table 11. . en the costs of phosphorus supplements erphosphate were charged to the respec- iups, the returns per cow were $191.41, if $287.89 and $234.72 for groups 1, 2, 3 “respectively. The respective returns per $13.91, $16.91, $20.39 and $19.97. “Cup 3, which received disodium phosphate fr, had a consistent but small advantage ‘ oup 2, fed bonemeal, in final weight of 'n number of calves dropped and weaned, ht of calves and in returns per acre and Cows in group 2 consumed 285 pounds meal per head and cows in group 3 con- f373 pounds of disodium phosphate. ,ws in group 1, which had no phosphorus 7- ent, were lighter, dropped fewer calves, ore irregular and slower to settle and i. lighter calves than the cows which re- supplemental phosphorus. Moup 4, which was on fertilized pasture, f» approximately 48 percent more calves " oup 3, 53 percent more than group 2 and '_ cent more than group 1. This group '. ed 44 percent more pounds of weaned ‘than group 3, 52 percent more than group . 126 percent more than group 1. Group 4 ,_= a small advantage over groups 2 and 3 weight per cow, and a marked advantage _oup 1. The principal advantage for group 1 the greater number of calves. Approxi- one ton of triple superphosphate was ap- , the pasture for each cow in group 4. DISCUSSION OF RESULTS _ was practical to supply phosphorus in ers, in a controlled water supply and by , 'ng pasture with superphosphate. The Q: per cow and per acre were greatest for ' 3, which received disodium phosphate in Group 2, fed bonemeal, was second in A: per cow and group 4, on fertilized pasture, 0nd in returns per acre. _ertilization with superphosphate permitted er rate of stocking and was effective in ing phosphorus when rainfall was favor- ’ It was less effective as a source of supple- ‘i; phosphorus during drouth than phosphorus j-feeders or in the drinking water. e complete effect of fertilization probably f» realized because drouth closed the experi- iin November 1946. Beneficial effect may gpersisted for a longer time. However, f. lanalyses of forage, soil and blood (Tables *7) and cases of creeps in the cows indicated ked decline in available phosphorus during ft 18 months of the experiment. S’ ere was ample forage in the pastures until l began in 1945. Afterward, there was evidence of over-stocking, particularly in pasture 4. Pastures 1 and 4 were stocked with 1 cow to approximately 14 and 12 acres, respectively, but the cows in the latter pasture were about 200 pounds heavier after the first calving and raised more calves. On the basis of 900-pound cows, pasture 1 carried 42 cows; pastures 2 and 3, 50 cows each; and pasture 4, 70 cows. The phos- phorus supplements and pasture fertilization, by increasing weights of cows and their production, imposed heavier rates of pasture use. Thus, it follows that, in addition to the number of head, production and weight are factors that should be considered in stocking. SUMMARY AND CONCLUSIONS An experiment was conducted on the Encino division of the King ranch near Falfurrias from 1941 to 1946 to determine the most practical methods of supplying phosphorus to range cattle and to determine the effect of applications of different phosphates on the yield and chemical composition of pasture forage. Phosphorus was supplied to cattle by feeding bonemeal in self- feeders, by adding disodium phosphate to a con- trolled water supply and by fertilizing pasture with triple superphosphate. Supplying phosphorus by all three methods gave good results and prevented phosphorus defi- ciency in normal seasons. The specific application of these findings, however, may be somewhat different, depending on the circumstances. For example, some ranchmen will find it feasible to supply phosphorus in a controlled water system. Others may find it more praticable to supply phosphorus supplements in self-feeders. Still others may prefer to supply phosphorus through pasture fertilization. The results show conclu- sively that the cattle will get the necessary phosphorus where any of these methods is used. Cows that were fed phosphorus supplements and cows on fertilized pasture produced larger calf crops and heavier calves at weaning time than cows that did not receive phosphorus supplements. The cows that did not receive phosphorus supple- ments produced 93 pounds of weaned calves per acre; cows that were fed bonemeal, 116 pounds; cows that received disodium phosphate in drink- ing water, 143 pounds; and cows on fertilized pasture, 176 pounds. Cows that did not receive a phosphorus sup- plement yielded a gross return of $13.91 per acre for the 4 years. After deducting the cost of phosphorus supplements or fertilizer, the cows that were fed bonemeal gave a return of $16.91 per acre; cows that received disodium phosphate in water, $20.39; and cows on fertilized pasture, $19.97. Feeding phosphorus supplements also greatly increased the amount of inorganic phosphorus in the blood stream. Supplying phosphorus in self- 15 feeders and in a controlled water system, in gen- eral, maintained a slightly higher level of blood phosphorus than pasture fertilization. Pasture fertilization, however, maintained an adequate phosphorus level in the blood stream except during the prolonged drouth in 1945 and 1946. If pasture fertilization is used, it probably will be necessary to reduce the rate of stocking and feed phosphorus supplements during drouth to supply adequate phosphorus to the cattle. This system of management will utilize all the advan- tages of pasture fertilization and, at the same time, provide sufficient phosphorus for cattle at all times. Applications of triple superphosphate, cal- cium metaphosphate, potassium metaphosphate and fused tricalcium phosphate increased the yield and phosphoric acid content of pasture forage. The increases in yield ranged from 33 to 84 per- cent, depending on the rate of application. Pound for pound of phosphoric acid, all the phosphates used apparently had about the same fertilizing value. In general, the phosphoric acid content of the grasses increased as the rate of phosphate appli- cation was increased. The heavier applications of triple superphosphate doubled the phosphoric acid content of the grasses and provided adequate phosphorus for range cattle in normal seasons. The application of phosphates apparently did not affect the protein content of grasses. The application of approximately 200 pounds of 48 percent triple superphosphate per acre in 1941 was effective in increasing the yield a, phosphorus content of pasture forage for 4 or. years. This amount of phosphate was profitab and is recommended Where ranchmen can use to advantage. a LITERATURE CITED 1. Black, W. H., Tash, L. H., Jones, J. M. and Kleber R. J ., Jr. Effect of phosphorus supplements on cat -, grazing on range deficient in this mineral. USD Tech. Bull. 856. 1943. Y 2. Fraps, G. S. and Fudge, J. F. Chemical composition soils of Texas. Tex. Agr. Exp. Sta. Bull. 549. 1937_ 3. Fraps, G. S. and Fudge, J. F. The chemical compositi, of forage grasses of the East Texas timber count,’ TeX. Agr. Exp. Sta. Bull. 582. 1940. 4. Fraps, G. S., Fudge, J. F. and Reynolds, E. B. Effect, fertilization of a Crowley clay loam on the chemi composition of forage and carpet grass, Axono affinis. Jour. Amer. Soc. Agron., 35:560-566. ‘; 5. Reynolds, E. B. and Wyche, R. H. Effect of fertiliz and lime on yield, protein content and phosphoric - content of pasture forage. Tex. Agr. Exp. Sta. P. 1039. 1946. J 6. Schmidt, H. Field and laboratory notes on a =p disease of cattle occurring o-n the Coastal Plains Texas. Tex. Agr. Exp. Sta. Bull. 319. 1924. . . 7. Schmidt, H. Feeding bonemeal to range cattle on = Coastal Plains of Texas. Tex. Agr. Exp. Sta. B 344. 1926. . 8. Stansel, R. H., Reynolds, E. B. and Jones, J. H. Pas ~‘ improvement in the Gulf Coast Prairie of Te Tex. Agr. Exp. Sta. Bull. 570. 1939. 4 “L.