Preweaning Growth of Angus- (Bus taums), Brahman- (Bus indictrs), and Tuli- (Sanga) Sired Calves and Reproductive Performance of their Brahman Dams!

Preweaning Growth of Angus- (Bus taums), Brahman- (Bus indictrs), and Tuli- (Sanga) Sired Calves and Reproductive Performance of their Brahman Dams! R. Browning, Jr.3, M. L. Leite-Brownine, D. A. Neuendorff, and R. D. Randel Texas Agricultural Experiment Station, Overton 75684 ABSTRACT: Calves born to Angus (A), Brahman gestation length, and PPI. Calf ADG and weaning (B), or Tuli (T) bulls and B cows were evaluated to weights were greater for AB (.g0 f.01 kg/d; 220.9 k determine sire breed of calf effects on preweaning calf 3.5 kg) than for TB (.81 f.01 kg/d; 200.4 k 3.0 kg) growth and reproductive performance of their dams. and BB calves (.78 k.01 kg/d; 198.8 & 3.5 kg). Records from 242 cow-calf pairs over 2 yr were used to Gestation lengths differed ( P <.Ol) among all calf assess birth weight, calf ADG, weaning weight, genotypes (284, 288, and 294 k 1 d for AB, TB, and gestation length, and postpartum interval to estrus BB, respectively). Postpartum intervals were shorter (PPI). The sire breed x sex of calf interaction was ( P <.05) for cows nursing BB calves (83 f 4 d) than important (P <.05) for birth weight, weaning weight, for cows nursing AB (95 f. 5 d) and TB calves (97 f 4 and gestation length. Birth weights of BB males (32.8 d). Tuli-sired F1 calves were inferior to Angus-sired F1 k.8 kg) were significantly heavier than for AB and TB calves and similar to straightbred Brahman calves in males (30.1 k.9 and 28.6 k.7 kg, respectively) and preweaningrowth. Crossbred calves had shorter BB females (29.4 k.7 kg). As a main effect, sire breed gestations but longer postpartum intervals than of calf affected ( P <.05) calf ADG, weaning weight, purebred calves. Key Words: Beef Breeds, Sire Evaluation, Pregnancy, Birth Weight, Weaning Weight, Postpartum Interval J. him. Sci. 1995. 73:2558-2563 Introduction Preweaning calf growth and cow reproductive efficiency are emphasized in cow-calf operations. Choice of sire breed influences preweaning calf performance (Reynolds et al., 1980, 1982; Brown et al., 1993). In a beef industry dominated by Bos taurus breeds such as Angus, Brahman (Bos indicus) have gained a unique place because of their environmental adaptation and attributes in crossbreeding (Franke, 1980; Turner, 1980). Evaluation of other nontraditional breeds is ongoing to characterize their potential This manuscript includes research supported and conducted by the Texas Agric. Exp. Sta., The Texas A&M Univ. System. 2This study was a contribution to the Western Regional Research Project W-112, Reproductive Performance in Domestic Ruminants. 3Present address: Cooperative Agricultural Research Program, Tennessee State Univ., 3500 John A. Merritt Blvd., Nashville 37209-1561. 4Present address: Dept. of Physiol., Meharry Medical College, Nashville, TN 37208. Received January 9, 1995. Accepted April 28, 1995. in U.S. beef production systems. The tropically adapted Tuli is one such breed. The Tuli is a Sanga breed that evolved from the mixing of Bos indicus and Bos taurus germplasm in Africa (Schoeman, 1989). Tuli cattle may possess a combination of adaptation and production attributes beneficial to beef production in the United States. The performance of Tuli cattle compares favorably to that of numerous other cattle breeds in African environments, as reviewed by Hetzel (1988). In Zimbabwe, Tuli-sired calves exhibited preweaning performance comparable to that of progeny of British sire breeds (Tawonezvi et al., 1988). Work with Sanga breeds in the United States began during the 1930s, when Africander cattle were used in crossbreeding programs along the Gulf Coast (Reynolds et al., 1980). Service sire breed may also affect cow reproductive performance. Sire breed of calf altered peripartum reproductive hormone profiles in dairy (Guilbault et al., 1985) and beef (Lammoglia et al., 1995) cows. Objectives of this study included comparing the preweaning growth of Tuli-, Angus-, and Brahman-sired calves and examining sire breed of calf effects on cow reproductive performance. 2558

Materials and Methods SIRE BREED OF CALF AND COW-CALF PERFORMANCE 2559 Location. This project was conducted at the Texas Agricultural Experiment Station, Overton (approximately 32"30'N, 95"W). Overton is at an elevation of 146.4 m. Mean monthly temperatures range from highs of 16 C and lows of 2 C in January to highs of 35 C and lows of 22 C in July. Annual precipitation is 1,143 mm. Daily relative humidity ranges from highs of 95% to lows of 50%. Animals. Over 2 yr, 242 calvings were recorded from 14 Angus ( A), 18 Brahman ( B), and 9 Tuli ( T) sires out of B cows (Table 1). Angus sires included a random sample of bulls representing a broad base of U.S. Angus genetics. Brahman sires were randomly selected to represent various Red and Gray American Brahman families. Tuli sires represented nine paternal lines exported from Zimbabwe to Australia. Tuli semen was imported to the United States from Australia. Predicted values of genetic merit from sire evaluations (i.e., EPD from sire summaries) were not used in the selection of Angus, Brahman, or Tuli bulls. Semen from the same bulls was used for AI in both years. Multiparous cows were 4 to 12 yr old and primiparous cows were 2.5 to 3.5 yr old. Cows grazed cool-season ryegrass and warm-season bermudagrass pastures. In 1992, postpartum cows received various protein supplements by random assignment as previously described (Triplett et al., 1993). Postpartum cows were not supplemented in 1993. Calving seasons were from mid-february to mid-may. At calving, cowcalf pairs were classified by parity (primiparous or multiparous), calf genotype (AB, BB, TB), and calf sex (bull or heifer). Calf weights were recorded within 24 h of birth. Through weaning, calves were not creepfed and bull calves were not castrated. Calves were weaned and weighed at 206 k 3 d of age in 1992 and at 186 f 4 d of age in 1993. Weaning weights were adjusted to 205-d values. Weights were not adjusted for age of dam because parity classes separated young cows from older cows. Estrus was detected by visual observation with the aid of epididymectomized bulls wearing chin-ball markers. Estrus detection ended when all cows were at least 90 d past calving in 1992 and 120 d past calving in 1993. Only cows with calves at side were included in the return to estrus data set. Weekly plasma concentrations of progesterone were used to confirm estrus dates. Statistical Analyses. This experiment was set up as a 3 x 2 factorial (sire breed of calf x calf sex) in a randomized complete block design. Birth weight, calf ADG through weaning, adjusted 205-d Female weaning weight, gestation length, and postpartum interval to estrus ( PPI) were analyzed by least squares ANOVA using the GLM procedure (Ott, 1988; SAS, 1988). Sources of variation in each model were sire breed of calf, bull nested within sire breed of calf, calf sex, and the interaction between sire breed and sex. Year and parity were included in all models because they had significant influences on the various traits as main effects. Preliminary analyses revealed no (P >.05) two-, three-, or four-way interactions involving year and(or) parity with sire breed and(or) sex for any trait measured. Breed of sire variation was tested using the random effect of bull within sire breed as the error term. All other factors, including the sire breed x sex interaction term, were tested using the residual term of the models. When the interaction of sire breed x sex or the main effect of sire breed was significant, Fisher's protected LSD procedure was used to separate least squares means using the PDIFF@ option of SAS (Ott, 1988; SAS, 1988). Results and Discussion Calves were lighter ( P <. Ol) at birth in 1992 than in 1993 (29.1 k.5 vs 31.2 +.5 kg). Calf birth weights were lighter ( P <.OO 1) from primiparous versus multiparous cows (29 f.5 vs 31.3 f.4 kg). The sire breed x sex interaction was important ( P <.OO 1) for birth weight (Figure 1). Within bull calves, BB calves were heavier than AB and TB calves, and AB calves were heavier than TB calves. Within sire breeds, a sex difference was detected ( P <.001) only in Brahmansired calves; BB bulls were heavier than BB heifers. As a main effect, sire breed was not a significant source of variation for birth weight (Table 2). Sire breed x sex interactions for birth weight have been observed previously from Bos taurus cows in which Bos indicus-sired calves had greater sex differences in birth weight than Bos taurus-sired calves (Notter et al., 1978; Bailey and Moore, 1980; Paschal et al., 1991). Although Brahman bulls sired calves :: 1 a Angus 0 Brahman 0 Tuli Male Sex of calf Figure 1. Effect of sire breed of calf on birth weights in male and female progeny born to Brahman cows. Error bars represent SE. a.brcmeans within males lacking a common superscript differ (P <.05). a/dmeans within males lacking a common superscript differ (P <.001).

~~ 2560 BROWNING ET AL. Table 1. Distribution of cow-calf pairs by sire breed of calf,sex of calf, year of record, and parity of cow Sire breed of calf and sex of calf Year 1992 1992 1993 1993 Tuli ~ g u s Brahman cow Parity of Male Female Male Female Male Female Multiparous Primiparous Multiparous Primiparous 8 217 15 9 17 3 12 11 5 5 6 8 16 18 14 15 10 10 4 11 4 9 4 with greater sex differences in birth weight than Bos taurus bulls, Franke et al. ( 1965) found Brahman cows to produce calves with minimal sex differences in birth weight compared to Bos taurus cows. The sire breed x sex interaction for birth weight may be related to dissimilar effects of Brahman sires and dams on birth weight. Brahman sires increase birth weights compared with Bos taurus sire breeds when bred to Bos taurus cows (Roberson et al., 1986; Comerford et al., 1987). This was evident in male calves out of Brahman cows in this study. Conversely, Brahman cows restrict birth weight in calves and minimize differences between service sire breeds compared with Bos taurus cows (Comerford et al., 1987; Ferrell et al., 1991). This was apparent in heifer calves or if calf sex was disregarded. Moyo (1990) also reported similar birth weights for BB, AB, and TB calves across sexes. The Bos indicus sire was the common factor from which the sire breed x sex interactions arose in this and past investigations. Brahman-sired males in utero seem able to overcome the ability of Brahman cows to restrict fetal growth. A factor associated with differences in the Y-chromosome derived from Brahman, Angus, or Tuli sires may be responsible for the heavier birth weights of BB bull calves. Brahman bulls have an acrocentric Y-chromosome, whereas Angus and Tuli bulls have a sub-metacentric Y-chromosome (Kieffer and Cartwright, 1968; Schoeman, 1989). Lower birth weights of TB males may also reflect the Tuli s smaller mature size. Mature weights of Tuli bulls average 800 kg (Gillin, 1985), whereas Angus bulls weigh an average 909 kg at maturity (ARS, 1991). Work investigating causes of sire breed x sex interactions for progeny birth weights involving Brahman sires may be needed. Calf ADG through weaning and 205-d weaning weights were greater ( P <.OO 1) in 1992 than in 1993 (.87 vs.79 f.01 kg/d; 218.5 k 3 vs 194.9 f 2.9 kg). Calves of primiparous cows had lower ( P <.05) ADG than calves of multiparous cows (.81 vs.84 f.01 kg/ d). However, panty of dam did not affect 205-d weaning weights. The sire breed x sex interaction was not significant for calf ADG. Bull calves had higher ( P <.05) preweaning ADG than heifer calves (.85 vs.81 f.01 kg/d). Sire breed of calf influenced ( P <.OOl) calf ADG through weaning (Table 2); AB calves outgained TB and BB calves. The sire breed x sex interaction was important (P <.05) for weaning weight (Figure 2). Within sire breeds, a sex difference for weaning weight was detected only in Brahmansired calves; BB bull calves were heavier ( P <.OO 1) than BB heifer calves. Within males, AB calves were heavier ( P <.05) than TB calves at weaning. Within females, AB calves were heavier ( P <.OO 1) than BB and TB calves. Across calf sexes, sire breed of calf influenced ( P <.001) weaning weights (Table 2); AB calves were heavier than TB and BB calves. Others have also reported preweaning ADG and weaning weights to be greater for AB than for BB calves (Reynolds et al., 1982; Brown et al., 1993). Heterosis likely enhanced preweaning performance of AB calves compared to BB calves. Heterosis estimates Table 2. Performance traits forcow-calf pairs when Angus, Brahman, and Tuli bulls were mated to Brahman cowsa Sire breed of calf Trait h%ps Brahman Tuli Birth weight, kg 30.3 k.6 31.2 f.6 29.1 f.5 Calf ADG, kg/d.90 f.old.78 2.Ole.81 f.olc Weaning weight, kg 220.9 k 3.5d 198.8 _+ 3.5e 200.4 f 3.0e Gestation length, d 284.0 f.sd 293.7 2 Se 288.4 f.7f Postpartum interval, d 95.4 k 4.gb 82.5 f 4.3Cd 97.4 i 4.3be aleast squares means 2 SE. bpcmeans within row with different superscripts differ (P <.05). d,e,fmeans within row with different superscripts differ (P <.01).

BREED SIRE OF CALF AND COW-CALF PERFORMANCE 2561 Angus 0 Brahman 0 Tuli gestation length as males were carried in utero 5 d longer than females (296.1 f 1 vs 291.3 f.9 d). 240-235 - Gestation lengths for male and female offspring were C 230 - a respectively, 288.5 and 288.3 f TB.9 d for and 285.3 - and 282.7 f 1.1 d for AB matings. calf Across sexes, ab gestation lengths differed ( P <.001) between each b sire breed (Table 2). Gestations were longest for BB, shortest for AB, and intermediate for TB matings. T d The extended period of time in utero of BB males d,t may be associated with their greater birth weights. A (D 225 positive relationship has been shown to exist between gestation length and birth weight in cattle (Andersen and Plum, 1965). Differences in gestation lengths due Male Female to service sire breed have been noted in past reports Sex of calf (Long, 1980; Paschal et al., 1991). The lengths of BB Figure Effect 2. of sire breed calf of on and AB gestations were similar to those found in 205-d adjusted weaning weights in male and female previous studies in which AB gestations were reported progeny born to Brahman cows. Error bars represent SE. to be shorter than BB gestations (Plasse et al., 1968; atbmeans within males lacking a common superscript Reynolds et al., 1980). Gestation lengths seem to be differ (P <.05). C.dMeans within females lacking a positively influenced by the expected gestation length common superscript differ (P <.001). of the service sire breed in crossbreeding. Gestation lengths in Angus average 280 d (Andersen and Plum, 1965; Reynolds et al., 1980). The gestation length of for weaning weight between Brahman and Angus TB matings suggests that purebred Tuli cattle have longer gestations than Angus. Other Sanga breeds cattle range from 12 to 23% (Peacock et al., 1978; have gestation lengths that average between 287 and Reynolds et al., 1982; Brown et al., 1993). Studies in 298 d (Rakha et al., 1971). Compared with cows with Zimbabwe found that TB were similar to AB and AB calves, cows delivering TB and BB calves may be greater than BB calves in preweaning ADG and at a disadvantage because fewer rebreeding days weaning weight (Moyo, 1990). However, studies in would be available to maintain yearly calving inter- Australia (VAB, 1993; J. Frisch, unpublished data) vals. showed ADG and weaning weights in TB and BB Year of calving did not influence PPI. By the end of calves to be similar, in agreement with the results the estrus detection period, 97.4% of the multiparous presented here. cows and 56% of the primiparous cows returned to In this study, TB calves did not have the Same estrus. Primiparous COWS had longer (P <.001) PPI advantage in growth rate that AB calves exhibited than multiparous cows (110.7 iz 4.7 vs 72 f 2.9 dl. OverBB calves. Calculated from the data of Mayo Calf sex and the sire breed x sex interaction were not (lggo), estimated heterosis between Brahman and Significant sources Of variation for PPI. Although Tuli cattle ( 6 %) Seems to be lower than heterosis similar ProPofiions returned to estrus (82.8, 83.7, and between Brahman and Angus cattle. Tuli are geneti- 80.8% of AB, BB, and TB group% respectively), PPI tally closer to Brahman than are bps, probably was affected ( P <.OS) by sire breed of calf (Table 2). because Sanga cattle evolved from a combination of cows nursing BB calves had significantly shorter PPI Bos indicus and Bos taurus genetics (Hetzel, 1988). than with AB and TB The smaller mature size of Tuli bulls relative to that Dystocia was not a problem in either year. In 1993, no multiparous and three primiparous cows (one TB of Angus bulls may have also contributed to differand two BB matings) required assistance at parturiences seen between AB and TB calves at weaning. tion. Prepartum steroid concentrations and the suck- Discrepancies in preweaningrowth comparisons ling calf are significant contributors to postpartum among TB, AB, and BB at various locations in cows (Nett, 1987). Sire breed of calf may reflect genotype x environment interactions and(or) genetic divergence within sire breeds across altered reproductive hormone concentrations before and after calving in milked primiparous dairy cows different populations* Using Angus sires was (Guilbault et al., 1985) and in beneficial than using Tuli sires for enhanced prewean- ( ~ suckled beef cows ~ et al., ~ 1995). ~ crossbreeding ~ ~ in l the i ~ ing Performance of Progeny when crossbreeding present study may have influenced PPI by modifying man COWS under the conditions of this experiment. peripartum endocrine profiles. Alternatively, AB and Gestation length was not i~flufmced by year Or TB calves may have placed more lactational and(orj parity. The sire breed X sex interaction was important suckling stress on COWS than BB calves. Previous (P =.05) for gestation length. Within sire breeds, only studies found crossbred calves to have greater suckthe BB group exhibited ( P <.001) a sex difference in ling activity and higher milk consumption compared to

2562 BROWNING ET AL. purebred calves (Cartwright and Carpenter, 1961; Reynolds et al., 1978). Brahman cows show lower reproductive performance in response to increased suckling stimulation and lactational demands (Franke, 1980; Turner, 1980; Browning et al., 1994). Calf performance is of primary interest in sire breed selection. However, consideration of expected gestation lengths and PPI associated with service sire breeds may be helpful in reproductive management. Further investigation into sire breed of calf effects on PPI in beef cows could yield useful information. In summary, sire breed influenced birth weights only in bull calves, suggesting that some factor associated with male fetuses affected birth weight. Preweaning ADG and weaning weights were greater for AB F1 calves than for TB F1 and BB purebred calves, whereas the latter two did not differ. Lengths of TB gestations were intermediate compared to longer BB and shorter AB gestations. Postpartum intervals to first estrus were shorter in Brahman cows rearing BB calves than in those raising AB or TB calves. Implications Choice of service sire breed is important because it affects cow-calf performance. Brahman cattle are an essential part of many crossbreeding programs, and thus Brahman x Brahman matings are necessary to produce purebred seedstock. Angus x Brahman matings seem preferable to Tuli x Brahman matings when crossbreeding to enhance preweaning calf growth. Tuli sires may be useful when moderate calf growth is desired. Postweaning, carcass, reproductive, and maternal traits of progeny should also be considered because they would further define the utility of Tuli sires relative to Angus sires. Crossbreeding Brahman cows shortened gestations but prolonged postpartum anestrus through undefined mechanisms. Literature Cited Andersen, H., and M. Plum. 1965. Gestation length and birth weight in cattle and buffaloes: A review. J. Dairy Sci. 48:1224. ARS. 1991. 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SIRE BREED OF CALF AND COW-CALF PERFORMANCE 2563 survival of Angus, Zebu and Zebu cross beef cattle. J. Anim. Sci. 512360. Roberson, R. L., J. 0. Sanders, and T. C. Cartwright. 1986. Direct and maternal genetic effects on preweaning characters of Brahman, Hereford and Brahman-Hereford crossbred cattle. J. him. Sci. 63:438. SAS. 1988. SAS Procedures Guide (Release 6.03). SAS Inst. Inc., Cary, NC. Schoeman, S. J. 1989. Recent research into the production potential of indigenous cattle with special reference to the Sanga. S. Mr. J. Anim. Sci. 19:55. Tawonezvi, H. P. R., H. K. Ward, J. C. M. Trail, and D. Light. 1988. Evaluation of beef breeds for rangeland weaner production in Zimbabwe. 2. Productivity of crossbred cows and heterosis estimates. Anim. Prod. 47:361. Triplett, B. L., D. A. Neuendorff, and R. D. Randel. 1993. Effects of by-pass protein supplementation on milk production, calf weight gain, and reproductive performance in Brahman cows. J. him. Sci. 71(Suppl. 1):24 (Abstr.). Turner, J. W. 1980. Genetic and biological aspects of Zebu adaptability. J. Anim. Sci. 50:1201. VAB. 1993. Tuli and Boran Cattle. Circ. VAB Genetics, Bacchus Marsh, Victoria, Australia.