Source: TEXAS A&M UNIVERSITY submitted to
BEEF CATTLE BREEDING AND MANAGEMENT
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0132468
Grant No.
(N/A)
Project No.
TEX06883
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2005
Project End Date
Sep 30, 2011
Grant Year
(N/A)
Project Director
Sanders, J. O.
Recipient Organization
TEXAS A&M UNIVERSITY
750 AGRONOMY RD STE 2701
COLLEGE STATION,TX 77843-0001
Performing Department
ANIMAL SCIENCE
Non Technical Summary
Lifetime productivity in Tuli- and Boran- crossbred cows has not been evaluated under North American conditions, information on heterosis retention for cow productivity traits in Bos indicus / Bos taurus crosses produced by inter se mating is lacking, and, to utilize information on the bovine genome, chromosomal locations must be identified for genes with major effects on birth, growth, disposition, carcass, tenderness, and cow productivity traits. The purpose of this research is to evaluate breed differences in tropically adapted breeds, to study heterosis retention in Bos indicus / Bos taurus crosses produced by inter se mating, and to identify genes with major effects on birth, growth, disposition, carcass, tenderness, and cow productivity traits in beef cattle.
Animal Health Component
90%
Research Effort Categories
Basic
10%
Applied
90%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
30333101080100%
Knowledge Area
303 - Genetic Improvement of Animals;

Subject Of Investigation
3310 - Beef cattle, live animal;

Field Of Science
1080 - Genetics;
Goals / Objectives
1.The three tropically adapted breeds, Tuli, Boran, and Brahman, will be evaluated by comparing the productivity of F1 cows sired by bulls of these breeds and out of both Hereford and Angus cows. 2. Levels of heterosis retention in cattle produced by inter se mating of Bos indicus / Bos taurus crossbred cattle will be evaluated in herds of straightbred Brahman, Angus, Nellore and Hereford, as well as first and second generation crosses of these breeds. 3. The third objective is to identify markers for genes with major effects on birth, growth, feed efficiency, carcass, tenderness, disposition, and cow productivity traits by evaluating second generation Bos indicus / British crossbreds produced by both embryo transfer and natural service.
Project Methods
To evaluate the tropically adapted breeds, Tuli, Boran and Brahman, F1 cows that were produced in 1992 and 1993, and currently being evaluated in TAES Project H-6883, would be used to continue the evaluation of tropically adapted breeds. These cows were produced by Hereford and Angus cows, artificially inseminated to Tuli, Boran, and Brahman bulls. Weight at birth and weaning are collected on all calves. Weight and pregnancy status of the cows are recorded in the fall when their calves are weaned. Cows are culled for severe injuries, poor health, or if they fail to wean a calf in any two years. To evaluate heterosis retention in Bos indicus / Bos taurus crosses, fourteen breeding herds have been established at McGregor, starting in 1994. These herds consist of a minimum of fifty cows per herd and include purebred herds of Brahman, Angus, Nellore, and Hereford, three F1 groups (Brahman / Angus, Brahman / Hereford, and Nellore / Angus), two F2 groups (Brahman / Angus and Brahman / Hereford), two first generation groups of 3/8 Bos indicus / 5/8 British breeding (3/8 Brahman 5/8 Angus and 3/8 Nellore 5/8 Angus), two second generation groups of the same 3/8 Bos indicus / 5/8 British breeding, and one four-breed crossbred group (1/4 Brahman 1/4 Angus 1/4 Nellore 1/4 Hereford). As in the breed evaluation study, weight at birth and weaning are collected on all calves, weight and pregnancy status of the cows are recorded in the fall when their calves are weaned, and cows are culled for severe injuries, poor health, or if they fail to wean a calf in any two years. To map genes associated with disposition, nutrient utilization, carcass and meat traits, and cow productivity, the development of a resource population has been initiated. Ten families of F2 Angus-Nellore full sibs are being generated over a four to five year period. These families are based on 10 Angus-Nellore F1 females and 4 Angus-Nellore F1 males that were produced in the heterosis retention project. The goal is to produce 20 heifers per F2 family through multiple ovulation of donor cows and embryo transfer. In addition to the embryo transfer calves, approximately 100 calves are produced annually by mating F1 Angus-Nellore sires to F1 and F2 Brahman-Hereford and Brahman-Angus dams. These calves are produced in multiple-sire breeding pastures and require DNA identification of their sires. The four sires of the embryo transfer families have been included in the bulls that produce these natural service calves; one of these four bulls is no longer available, but the other three are used. The natural service calves identified as being sired by these four bulls are evaluated in the same way as the embryo transfer calves. QTL (quantitative trait loci) scans will be initiated for birth, disposition, growth, carcass and tenderness traits when genotyping is completed. As cow productivity data is collected, additional scans will be done.

Progress 10/01/05 to 09/30/11

Outputs
OUTPUTS: In 1991 and 1992, both Hereford (H) and Angus (A) cows were artificially inseminated to 9 Tuli, 8 Boran, and 15 Brahman (B) bulls. The F1 females from these matings were retained to evaluate lifetime productivity. Several sire breeds were used, and breed of sire of calf is confounded with year. Calves were produced from 1994 to 2011. Cows were culled for severe injuries or for poor health. Until they were 14 years old, they were also culled for at least 2 failures to have or wean a calf. After the cows reached 14 years of age, they were culled for any additional failure to wean a calf, regardless of previous record. Initially, there were 55 B-, 36 Boran- and 52 Tuli- sired cows. A student completed an M.S. thesis this year based on the cow productivity data from this study. Breeding herds were established, starting in 1995, to evaluate heterosis retention in cattle produced from the inter se mating of Bos indicus/Bos taurus crosses. Primary emphasis is on cow productivity. Comparison herds are made up of a minimum of 50 cows each in 14 different groups; the cows have been retained to evaluate lifetime productivity. All females in the comparison herds were produced at the McGregor station. The 14 breeding groups include four purebred groups (A, B, H and Nellore (N)), three F1 groups (BA, BH and NA), two F2 groups (BA and BH), two first-generation groups of 3/8 Bos indicus / 5/8 British breeding (3/8 B / 5/8 A and 3/8 N / 5/8 A), two second-generation groups of the same 3/8 Bos indicus / 5/8 British breed composition and one four-breed crossbred group (BANH, which is 25% of each breed in the purebred groups). The BH F1 group includes both reciprocal crosses. The BA and NA F1 groups include only cows out of A dams and by B and N bulls, respectively. The BH F2 group includes all four possible combinations of F1 matings, giving the opportunity to evaluate cows differing in sources of X chromosomes and maternal cytoplasm. All cows in the BA F2 group are out B sired F1 cows, but the group includes cows sired by both B sired and A sired F1 bulls. The same culling criteria were used as in the Tuli/Boran/Brahman evaluation. A student completed an M.S. thesis this year based on the cow productivity data from this study. A genomics project was started in 2002 with the primary objective of finding genes with major effects on cow productivity traits and secondary objectives of finding genes with major effects on disposition, feed efficiency, and carcass and meat traits. Full sib embryo transfer families of F2 NA calves were produced out of 13 donor cows and by a total of 4 bulls. In addition, 4 half-sib families were produced by mating the same 4 F1 NA sires, by natural service, to F1 and F2 BH and BA dams. A student completed a Ph.D. dissertation this year based on the cow productivity data from this study. Two additional cycles of the genomics project have been started. Cycle 2 involves the production by natural service of all 4 types of NA reciprocal F2 crosses, to continue our evaluation of reciprocal differences in Bos indicus/Bos taurus crosses. Cycle 3 involves the production by natural service of F3 crossbreds from cattle produced in Cycle 1. PARTICIPANTS: The principle investigator for this project is J.O. Sanders. J.E. Sawyer is the superintendent of the McGregor Station, where all the live animal research for the project is conducted. D.G. Riley, C.A. Gill, and A.D. Herring are co-investigators. In addition, J.E. Sawyer and P.K. Riggs are collaborators in the genomics component. A.J. Cooper, C.T. Muntean, L. Boenig, M.E. Williams, M.D. Obeidat, and L.L. Hulsman are graduate students who were involved in conducting the project and received training from the project in 2011. TARGET AUDIENCES: The target audience for this project includes beef cattle producers, extension agents and specialists, and research workers, professors, and students in animal science, animal breeding and genetics, beef cattle production, quantitative genetics, and genomics. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period

Impacts
Averages for calf crop weaned for Brahman (B) and Hereford (H) cows in the heterosis retention study were .69 and .74, respectively, through 2009. The means for these same cows, through 2003, were .59 and .72, respectively. The value for B was much lower in the earlier analysis, because few calve as 2 year olds, and the 2 yr old record made up a larger fraction of the records. The B/H F1 average was .83 (reciprocals combined), through 2009, giving a heterosis (HV) estimate of .12. For the reciprocal F1 crosses, the F1 HB cows (by H bulls and out of B cows) had higher calf crop (0.85) than the F1 BH (by B bulls and out of H cows) cows (0.81). All four possible types of B/H F2 cows were evaluated in approximately equal numbers (12 or 13 head, originally, in each group). The average calf crop for the F2 cows (reciprocals combined) was .76, giving an estimate of HV retained in the F2 generation .05 or about 40% of the F1 HV, which does not differ greatly from the 50% expected from the dominance model. However, there were large differences in calf crop among the different types of F2 cows. The F2 cows by HB bulls had higher average calf crop weaned than those by BH bulls. Average calf crop values were .59, .67, .88, and .90 for F2 BH (by F1 BH bulls and out of F1 BH females), F2 BH x HB (by F1 BH bulls and out of F1 HB females), F2 HB (by F1 HB bulls and out of F1 HB females), and F2 HB x BH (by F1 HB bulls and out of F1 BH females), respectively. The earlier results from Australia, which indicated that all of the F1 HV for cow reproductive traits was lost in B/British F2 crosses, were based on cattle that were equivalent to the F2BH cows in the current study. That is, all their F1 cattle used to produce the F2 generation were by B bulls and out of British cows. All of the B/Angus F2 cows in our heterosis retention study are out of B sired F1 cows, but the group includes cows sired by both B sired and Angus (A) sired F1 bulls. From an earlier analysis, the HV for calf crop weaned in B/A F1 cows was .11, similar to the recent estimate in B/H F1 cows. From that analysis, the average calf crop in the B/A F2 cows was below the mid-parent average, but, as in the B/H evaluation, the cows with taurus sired sires had higher reproductive performance than those with B sired sires. Based on colors of F2 cattle in the genomics project, there is evidence of a gene on BTA 6 that modifies the effect of the dominant gene for black at the extension locus. This modifying gene appears to coincide with a cluster of tyrosine kinase receptor genes that includes KIT. Cattle that carry this gene and that are heterozygous for dominant black and wild type, have a reddened color, that can be almost totally red or tan, in the most extreme cases. These reddened animals have black pigmentation on the nose and feet and, at least most, have some black pigmentation on other parts of the body. Based on analysis of data from the Cycle 1 F2 cows in the genomics project, there is strong evidence for a major gene effecting udder support score on BTA 5. There is also evidence for a gene affecting teat diameter at or near this location and one affecting teat length on BTA 28.

Publications

  • Boenig, L., D. G. Riley, J. O. Sanders, J.A.Sawyer. 2011. Heterosis for calving and weaning rates in Brahman- Hereford cows. American Society of Ani. Sci., Southern Section Abstracts.
  • Cooper, A.J. 2011. Evaluation of udder conformation, weight, body condition, reproduction, disposition, and calf growth, in Bos indicus-Bos taurus cows. Ph.D. Dissertation, Texas A&M Univ., College Station.
  • Hulsman, L. L., S.O. Peters, J. O. Sanders, A.D. Herring, C. A. Gill, P.K. Riggs, D. G. Riley. 2011. Whole genome QTL mapping for overall disposition at weaning in Nellore-Angus cattle using Bayesian Inference. American Society of Ani. Sci., Southern Section Abstracts.
  • Hulsman, L. L., S.O. Peters, J. O. Sanders, A.D. Herring, C. A. Gill, D. G. Riley. 2011. Prediction of genomic estimated breeding values for temperament at weaning in Bos indicus crossbreds using Bayesian Inference. J. Anim. Sci. 89 (Suppl. 1): 423 (Abstract #341 (American Society of Ani. Sci., National Meeting Abstracts).
  • Hulsman, L.L., S.O. Peters, , J.O. Sanders, A.D. Herring, C.A. Gill, and D.G. Riley. 2011. The use of genomic selection in the management of beef cattle - is it realistic Proceedings of the 57th Annual Beef Cattle Short Course. Pp E28 - E-37.
  • Muntean, C.T. 2011. Evaluation of F1 cows sired by Brahman, Boran, and Tuli bulls for reproductive and performance traits and cow longevity. M.S. Thesis, Texas A&M Univ., College Station.


Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: In 1991 and 1992, both Hereford (H) and Angus (A) cows were artificially inseminated to Tuli (n=9), Boran (n=8), and Brahman (n=15) bulls. The F1 steers from these matings were fed and slaughtered to evaluate growth, carcass, and tenderness traits. The F1 females from these matings, which were born in 1992 and 1993, were retained for evaluation of lifetime productivity. Heifers were exposed by natural service to A bulls to calve in the spring and have their first calves at two yr of age. All cows were bred to Brangus bulls for their second calves. Cows in the older group (born in 1992) were also bred to Brangus bulls for their third calves. Starting with that breeding season (1995), all cows of both ages were bred to the same bulls in any given year. Several sire breeds have been used, and breed of sire of calf is confounded with year. Calves have been produced from 1994 to 2010. Cows have been culled for severe injuries or for poor health. Until they were fourteen years old, they were also culled for at least two failures to have or wean a calf. Since the cows have reached fourteen years of age, they have been culled for any additional failure to wean a calf, regardless of previous record. Initially, there were 55 Brahman-, 36 Boran- and 52 Tuli- sired cows. An M.S. student is updating the analyses of the cow productivity data from this study. Breeding herds were established, starting in 1995, at the McGregor station to evaluate heterosis retention in cattle produced from the inter se mating of Bos indicus/Bos taurus crosses. Primary emphasis is on cow productivity. Comparison herds are made up of a minimum of 50 cows each in 14 different groups; the cows have been retained to evaluate lifetime productivity. All females in the comparison herds were produced at the McGregor station. The 14 breeding groups include four purebred groups A, Brahman (B), H and Nellore (N)), three F1 groups (B/A (BA), B/H (BH) and N/ A (NA)), two F2 groups (BA and BH), two first-generation groups of 3/8 Bos indicus / 5/8 British breeding (3/8 B / 5/8 A and 3/8 N / 5/8 A), two second-generation groups of the same 3/8 Bos indicus / 5/8 British breed composition and one four-breed crossbred group (BANH, which is 25% of each breed in the purebred groups). The BH F1 group includes both reciprocal crosses. The BA and NA F1 groups include only cows out of A dams and by B and N bulls, respectively. The BH F2 group includes all four possible combinations of F1 matings, giving the opportunity to evaluate cows differing in source of X chromosomes and maternal cytoplasm. All cows in the BA F2 group are out B sired F1 cows, but the group includes cows sired by both B sired and A sired F1 bulls. First females for the comparison groups were produced in 1994. The same culling criteria were used as in the Tuli/Boran/Brahman evaluation. Three M.S students are currently updating the analyses of the cow productivity data from this study. A genomics project was initiated in 2002 with one objective of finding genes with major effects on cow productivity in F2 NA cows. A second cycle of this genomics project has been initiated to evaluate genetic effects in reciprocal F2 NA cows. PARTICIPANTS: The principle investigator for this project is J.O. Sanders. J.E. Sawyer is the superintendent of the McGregor Station, where all the live animal research for the project is conducted. D.G. Riley, C.A. Gill, and A.D. Herring are co-investigators. In addition, J.E. Sawyer and P.K. Riggs are collaborators in the genomics component. A.J. Cooper, C.T. Muntean, L. Boenig, M.E. Williams, M.D. Obeidat, and L.L. Hulsman are graduate students who were involved in conducting the project and received training from the project in 2010. TARGET AUDIENCES: The target audience for this project includes beef cattle producers, extension agents and specialists, and research workers, professors, and students in animal science, animal breeding and genetics, beef cattle production, quantitative genetics, and genomics. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
In the Tuli (Tu), Boran (Bo), Brahman (Br) comparison, there were large differences due to breed of sire in the F1 calves; birth weight least squares means for the Tu-, Bo-, and Br-sired calves were 36.4, 40.3, and 44.0 kg, respectively. Birth weights for calves out of crossbred cows have not differed significantly by sire breed of cow; through 2009, the averages have ranged from 34.0 to 34.1 kg in the calves out of Bo and Br crossbred cows. For weaning weight, the Br-sired F1 calves were significantly heavier (234.3 kg), than calves by the Bo and Tu bulls (217.1 and 209.1 kg, respectively). Calves out of all three groups of F1 cows differed significantly for weaning weight (236.7, 217.5, and 197.2 kg for those out of Br, Bo and Tu crosses, respectively). Average mature cow weight (in the year 2000, when the cows born in 1993 were 7 and those born in 1992 were 8 yr of age) was significantly higher for the Br crosses (601.9 kg) than for the Bo (518.6 kg) and Tu crosses (515.4 kg), which did not differ significantly; means for condition score in 2000 were 5.9, 6.2 and 5.6 for the Br, Bo and Tu crosses, respectively. Using the cow weights in 2000 and the weaning weights through 2009, weaning weight of the calf as a proportion of cow weight are .393, .419, and .383, for those out of the Br, Bo, and Tu cross cows; when expressed as a ratio of calf weight to the .75 power of cow weight, the corresponding proportions are 1.95, 2.00, and 1.82. Calf crop percentages born have been 94.4, 89.2, and 87.2, and calf crop percentages weaned (CCW) have been 89.4, 84.3 and 81.0 for the Bo, Tu and Br crosses, respectively. Using the above values for weight of calf per unit of cow weight and these values for CCW, weight of calf weaned per unit of cow weight exposed to breeding are .318, .375, and .323 for calves out of the Br, Bo, and Tu cross cows. In terms of metabolic weight (.75 power of cow weight), weight of calf weaned per unit of metabolic weight of cow exposed to breeding are 1.58, 1.79, and 1.53 for calves out of the Br, Bo, and Tu cross cows. Of the initial 52 Tu-, 36 Bo- and 55 Br-sired cows, 14, 20 and 18, respectively, remained in the herd prior to culling in 2007, when the remaining cows were 14 and 15 years of age. After culling, 8, 17, and 10 remained, respectively. Of the original cows, 15, 47 and 18% of the Tu, Bo and Br crosses remained in the herd after culling in 2007. In 2008, 8, 17, and 9, respectively, were still in the herd prior to culling, and 5, 12, and 7 (10, 33, and 13%, respectively) remained after culling, when they were 15 and 16 years of age. Before culling in 2009, 4, 12, and 6 of the Tu-. Bo-, and Br-sired cows remained in the herd, and 1, 8, and 4 (2, 22, and 7%, respectively of the original cows) remained after culling, when they were 16 and 17 years of age. Although weaning weights have been heaviest for the calves out of the Brahman sired cows, the Boran cross cows have had higher reproductive rates and longer productive lives and have weaned a higher percentage of their own mature weights than either the Brahman or Tuli crossbred cows and have had more moderate mature weights than the Brahman cross cows.

Publications

  • Thrift, F. A., J. O. Sanders, M. A. Brown, A. H. Brown, Jr., A. D. Herring, D. G. Riley, S. M. DeRouen, J. W. Holloway, W. E. Wyatt, R. C. Vann, C. C. Chase, Jr., D. E. Franke, L. V. Cundiff, and J. F. Baker. 2010. Review: Preweaning, Postweaning, and Carcass Trait Comparisons for Progeny Sired by Subtropically Adapted Beef Sire Breeds at Various US Locations. Professional Animal Scientist 26:451-473.
  • Hulsman, L. L., J. O. Sanders, D. G. Riley, C. A. Abbey, C. A. Gill. 2010. Identification of a major gene that interacts with MC1R to modify black coat color in a Nellore-Angus F2 population. Texas A&M AgriLife Student Research Poster Competition, College Station, TX, Jan. 11-15, 2010 (Abstr.).
  • Hulsman, L. L., J. O. Sanders, D. G. Riley, C. A. Abbey, C. A. Gill. 2010. Identification of loci interacting with Melanocortin-1 receptor to modify black coat color in an F2 Nellore-Angus population. Proc. Texas Genetics Society Annual Meeting, Houston, TX, Mar. 25-27, 2010 (Abstr.).


Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: A genomics project was initiated in 2002 with the major objective of finding genes with major effects on cow productivity traits and secondary objectives of finding genes with major effects on disposition, feed efficiency, carcass and meat traits, coat color, and horned/scurred/polled. Embryo transfer (ET) families of F2 Nellore/Angus (NA) calves were produced, with the goal of 40 calves per family in 10 full sib families. The families are all out of different donor cows and by a total of 4 bulls; some of the donors had to be replaced, so there are 13 ET families. ET calves were born in both the spring and fall from 2003 to 2006 and in the spring of 2007, for a total of 9 calf crops. In addition to the ET calves, calves were produced by mating the same 4 F1 NA sires by natural service (NS) to F1 and F2 Brahman-Hereford and Brahman-Angus dams, producing half-sib families. These calves were produced in multiple-sire breeding pastures and required DNA identification of their sires. The NS calves were born in the spring from 2003 to 2007. A total of 478 ET calves and 266 NS calves were produced. All of the F1 NA parents that were used to produce the ET calves were by Nellore bulls and out of Angus cows. As a second cycle of this genomics project, reciprocal F2 NA crosses are being produced by NS to continue our evaluation of reciprocal differences in Bos indicus/Bos taurus crosses. Starting in 2006, reciprocal F1 NA bulls and heifers have been retained and combined with the Nellore-sired F1 NA cows and bulls from earlier studies to produce these reciprocal F2 crosses. Only matings of Nellore-sired bulls to Nellore-sired cows were used to produce the NS F2 calves that were born in 2008. Both Nellore-sired and Angus-sired F1 bulls were mated to Nellore-sired F1 cows in 2008 to produce the calves that born in 2009. Both Nellore-sired and Angus-sired F1 bulls were mated to both Nellore-sired and Angus-sired F1 cows in 2009. These matings will be continued until fifty females of each of the four reciprocal types of F2s are available for the evaluation of cow productivity. To the extent possible, animals of the four reciprocal types will be produced and evaluated as contemporaries. Matings for a third cycle of this genomics project were initiated in 2008 by mating F2 bulls and cows that were produced in the ET phase of the first cycle. The F3 animals produced in this cycle will be used for fine mapping of birth, weaning, disposition, and cow productivity traits. Breeding herds have been established, starting in 1995, at the McGregor station to evaluate heterosis retention in cattle produced from the inter se mating of Bos indicus/Bos taurus crosses. Primary emphasis is on cow productivity. Comparison herds are made up of a minimum of 50 cows each in 14 different groups; the cows have been retained to evaluate lifetime productivity. All females in the comparison herds were produced at the McGregor station. First females for the comparison groups were produced in 1994. In 2009 an M.S student analyzed the color variation in heterozygotes at the extension locus from the first cycle of the genomics project for her thesis research. PARTICIPANTS: The principle investigator for this project is J.O. Sanders. J.E. Sawyer is the superintendent of the McGregor Station, where all the live animal research for the project is conducted. D.G. Riley, C.A. Gill, and A.D. Herring are co-investigators. In addition, J.E. Sawyer and P.K. Riggs are collaborators in the genomics component. A.J. Cooper, S.F. Cunningham, C.T. Muntean, and L.L. Hulsman are graduate students who were involved in conducting the project and received training from the project in 2009. TARGET AUDIENCES: The target audience for this project includes beef cattle producers, extension agents and specialists, and research workers, professors, and students in animal science, animal breeding and genetics, beef cattle production, quantitative genetics, and genomics. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Least squares means for calf crop weaned for Brahman (B), Angus (A), and Hereford (H) cow in the heterosis retention study were .59, .83, and .72, respectively. The value for B is low, because few calve as two year olds. Brahman/Angus (all sired by B bulls and out of A cows) and Brahman/Hereford F1 averages were .82 and .82 (reciprocals combined), giving heterosis estimates of .11 and .165. For the reciprocal Brahman/Hereford F1 cows, the F1 HB cows (by Hereford bulls and out of Brahman cows) had higher calf crop weaned (0.88) than the F1 BH (by Brahman bulls and out of Hereford cows) cows (0.79). Two types of F2 Brahman/Angus cows were produced; all had Brahman sired F1 dams, but both Brahman sired and Angus sired F1 bulls were used. Those with Angus-sired sires (F2 AB x BA) had higher average calf cropped weaned (0.67) than those (F2 BA) with Brahman-sired sires (0.59). Note that both of these values are lower than the mid-parent average and considerably lower than would be predicted from the dominance model. There were even larger differences in calf crop weaned among the different types of F2 Brahman/Hereford cows, of which all four possible types of reciprocal crosses were produced. The F2 cows by HB bulls had higher adjusted mean for calf crop weaned than those by BH bulls. In this analysis, the overall mean for the four types of F2 Brahman/Hereford cows was higher than predicted from the dominance model. From another analysis (that included more data on F2 cows but did not include the straightbred and F1 data), adjusted means were 0.57, 0.84, 0.62, and 0.82 for F2 BH (by F1 BH bulls and out of F1 BH females), F2 HB (by F1 HB bulls and out of F1 HB females), F2 BH x HB (by F1 BH bulls and out of F1 HB females), and F2 HB x BH (by F1 HB bulls and out of F1 BH females), respectively. For both the F2 Brahman/Angus and the F2 Brahman/Hereford cows, those with British-sired sires had higher calf crop weaned than those with Brahman-sired sires. The F2 cows by BH bulls were heavier than those by the HB bulls; averaged across all ages, fall cow weights for F2 BH, F2 HB, F2 BH x HB, and F2 HB x BH, were 534, 493, 518, and 477 kg, respectively. Cows have been culled for severe injuries, for poor health, or for at least two failures to have or wean a calf. In the fall of 2009, the Brahman/Angus F2 cows (reciprocals combined) ranged from 10 to 12 years of age, and the Brahman/Hereford F2 cows (reciprocals combined) ranged from 10 to 13 years of age. Of the initial 26 F2 BA and 25 F2 AB x BA cows, 4 and 10, respectively, remained in the herd prior to culling in 2009 (i.e., 15 and 40%, respectively). After culling, 3 and 9 remained, respectively (12 and 36%, respectively). Of the original 13 F2 BH, 12 F2 BH x HB, 13 F2 HB x BH, and 12 F2 HB cows, 2, 1, 8, and 6 (15, 8, 62, and 50%) remained in the herd prior to culling in 2009. After culling, 2, 1, 6, and 5 (15, 8, 46, and 42%) remained, respectively.

Publications

  • No publications reported this period


Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: A genomics project was initiated in 2002 with the major objective of finding genes with major effects on cow productivity. Embryo transfer (ET) families of F2 Nellore/Angus (NA) calves were produced, with the goal of 40 calves per family in 10 full sib families. The families are all out of different donor cows and by a total of 4 bulls; some of the donors had to be replaced, so there are 13 ET families. ET calves were born in both the spring and fall from 2003 to 2006 and in the spring of 2007, for a total of 9 calf crops. In addition to the ET calves, calves were produced by mating the same 4 F1 NA sires by natural service (NS) to F1 and F2 Brahman-Hereford and Brahman-Angus dams, producing half-sib families. These calves were produced in multiple-sire breeding pastures and required DNA identification of their sires. The NS calves were born in the spring from 2003 to 2007. A total of 478 ET calves and 266 NS calves were produced. All of the F1 NA parents that were used to produce the ET calves were by Nellore bulls and out of Angus cows. As a second cycle of this genomics project, reciprocal F2 NA crosses are being produced by NS to continue our evaluation of reciprocal differences in Bos indicus/Bos taurus crosses. Starting in 2006, reciprocal F1 NA bulls and heifers have been retained and combined with the Nellore-sired F1 NA cows and bulls from earlier studies to produce these reciprocal F2 crosses. Only matings of Nellore-sired bulls to Nellore-sired cows were used to produce the NS F2 calves that were born in 2008. Both Nellore-sired and Angus-sired F1 bulls were mated to Nellore-sired F1 cows in 2008 to produce the calves to be born in 2009. Both Nellore-sired and Angus-sired F1 bulls will be mated to both Nellore-sired and Angus-sired F1 cows beginning in 2009 to produce the remaining cattle in this cycle of this study. Matings will be continued until fifty females of each of the four reciprocal types of F2s are available for the evaluation of cow productivity. To the extent possible, animals of the four reciprocal types will be produced and evaluated as contemporaries. Matings for a third cycle of this genomics project were initiated in 2008 by mating F2 bulls and cows that were produced in the ET phase of the first cycle. The F3 animals produced in this cycle will be used for fine mapping of birth, weaning, disposition, and cow productivity traits. Breeding herds have been established, starting in 1995, at the McGregor station to evaluate heterosis retention in cattle produced from the inter se mating of Bos indicus/Bos taurus crosses. Primary emphasis is on cow productivity. Comparison herds are made up of a minimum of 50 cows each in 14 different groups; the cows have been retained to evaluate lifetime productivity. All females in the comparison herds were produced at McGregor. First females for the comparison groups were produced in 1994. In 2008 an M.S student analyzed the cow productivity data from the first cycle of the genomics project for his thesis research and a Ph.D. student analyzed the birth and weaning data from the calves from the first cycle of the genomics project. PARTICIPANTS: The principle investigator for this project is J.O. Sanders. J.E. Sawyer is the superintendent of the McGregor Station, where all the live animal research for the project is conducted. C.A. Gill, and A.D. Herring are co-investigators. J.E. Sawyer and P.K. Riggs are collaborators in the genomics component. R.R. Funkhouser, A.J. Cooper, S.F. Cunningham, and C.T. Muntean are graduate students who were involved in conducting the project and received training from the project in 2008. TARGET AUDIENCES: The target audience for this project includes beef cattle producers, extension agents and specialists, and research workers, professors, and students in animal science, animal breeding and genetics, beef cattle production, and quantitative genetics. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
IIn the embryo transfer (ET) calves from the first cycle of the genomics project, calves by bull 432H had the lowest birth (31.3 kg) and weaning weights (213.8 kg) and longest gestations (282.2 d). Natural service (NS) calves by 432H also had the lowest birth (34.5 kg) and weaning weights (223.6 kg). ET calves by 437J had the highest birth weights (34.0 kg), but, in NS calves, those by 551G were heaviest (36.8 kg). Calves by bull 297J had the heaviest weaning weights in both ET (225.0 kg) and NS calves (243.5 kg) and shortest gestations (279.3 d) in ET calves. In an analysis of the cow data through the 2007 calf crop, among calves out of the cows produced by ET, those out of daughters of 432H were lowest in both birth weight (27.3 kg) and weaning weight (175.7 kg). Those out of daughters of 551G were heaviest at birth (31.7 kg) and those out of daughters of 297J were heaviest at weaning (209.1 kg). Among calves out of the cows produced by NS, those out of daughters of 432H had the second lightest average birth weights (27.1 kg) and the lightest weaning weights (188.1 kg). Those out of daughters of 437J had the highest average birth weights (28.7 kg) and weaning weights (207.3 kg). Among full sib families of ET calves, two of the families sired by 432H (families 72 and 73) had the lowest average birth weights (30.6 kg for both families); one of the families by 437J (family 74) had the highest average birth weight (36.4 kg). This was a small family (8 calves), but a large family (family 83; n= 38) by 437J had the third highest average birth weight (34.8 kg). Two large families by 551G (families 80 and 77, with 69 and 41 calves, respectively) had the second and fourth highest average birth weights (35.2 and 34.5 kg, respectively). The two families with the lowest average birth weights (families 72 and 73, both by 432H) also had the lowest weaning weights (212.5 and 206.9 kg, respectively). A large family by 297J (family 71; n = 70) had the second heaviest average weaning weight (230.7 kg); this family had the fifth heaviest birth weight (34.3 kg). Family 77, that had the fourth highest average birth weight, had the heaviest average weaning weight (231.4 kg). Families 80 and 83, that had the second and third heaviest average birth weights, had the fourth and third heaviest average weaning weights, respectively. The small family that had the heaviest average birth weight (family 74 by 437J) had the third lowest average weaning weight. The difference in average birth weights between bull and heifer calves was small in the calves from the first cycle of the project, especially in the ET calves. In the ET calves (F2 Nellore-Angus (NA) calves), the difference was only 0.6 kg (33.3 vs. 32.7 kg, in bulls and heifers, respectively). In the NS calves (by F1 NA bulls and out of 1/2 Brahman 1/2 British cows), the difference was 1.1 kg (36.6 vs. 35.5 kg,). In the cow data through the 2007 calf crop, the calves were all sired by Angus bulls. In the calves out of the cows produced by ET, bull calves were 1.5 kg heavier than heifers (30.0 vs. 28.5 kg). In the calves out of the cows produced by NS, bulls were 1.9 kg heavier than heifers (28.4 vs. 26.5 kg).

Publications

  • Funkhouser, R.R. 2008. Evaluation of disposition scores in Bos indicus/Bos taurus cross calves at different stages of production. M.S. Thesis, Texas A&M Univ., College Station.
  • Funkhouser, R.R., J.O. Sanders, A.D. Herring, C.A. Gill, D.K. Lunt, and J.E. Sawyer. 2008. Evaluation of disposition scores in Bos indicus/Bos taurus cross calves at weaning. American Society of Ani. Sci., Southern Section Abstracts.
  • Cunningham, S. F., A.H. Maiga, K.L. Key, A.E. Ducoing, J.O. Sanders, A.D. Herring, and D. K. Lunt. 2007. Evaluation of F1 cows sired by Brahman, Boran, and Tuli for reproductive and maternal performance and cow longevity. 2007 Beef Cattle Research in Texas. Pp 23-26.
  • Sanders, J.O. 2008. McGregor Genomics: Background and Procedures. Proceedings of the 54th Annual Beef Cattle Short Course. Pp N7 - N-17.


Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: Breeding herds have been established, starting in 1995, at the McGregor station to evaluate heterosis retention in cattle produced from the inter se mating of Bos indicus/Bos taurus crosses. Primary emphasis is on cow productivity. Comparison herds are made up of a minimum of 50 cows each in 14 different groups. All females in the comparison herds were produced at McGregor. First females for the comparison groups were produced in 1994. The 14 breeding groups include four purebred groups (Angus (A), Brahman (B), Hereford (H) and Nellore (N)), three F1 groups (Brahman/Angus (BA), Brahman/Hereford (BH) and Nellore/Angus (NA)), two F2 groups (BA and BH), two first-generation groups of 3/8 Bos indicus / 5/8 British breeding (3/8 Brahman / 5/8 Angus (3B5A) and 3/8 Nellore / 5/8 Angus (3N5A)), two second-generation groups of the same 3/8 Bos indicus / 5/8 British breed composition and one four-breed crossbred group (BANH, which is 25% of each breed in the purebred groups). Fifty or more females have been produced from all groups. Cows of the fourteen groups have been retained to evaluate lifetime productivity. The BH F1 group includes both reciprocal crosses. The BA and NA F1 groups include only cows out of Angus dams and by Brahman and Nellore bulls, respectively. The BH F2 group includes all four possible combinations of F1 matings, giving the opportunity to evaluate cows differing in source of X chromosomes and maternal cytoplasm. All cows in the BA F2 group are out Brahman sired F1 cows, but the group includes cows sired by both Brahman sired and Angus sired F1 bulls. The 3B5A cows were produced from two types of matings (3/4 Brahman 1/4 Angus bulls mated to Angus cows and 1/4 Brahman 3/4 Angus bulls mated to F1 cows), with different amounts of heterosis expected based on the dominance model. The 3N5A cows were produced from three types of matings, also with different amounts of heterosis expected based on the dominance model. These matings included (a) 1/4 Nellore 3/4 Angus bulls mated to F1 cows, (b) 3/4 Nellore 1/4 Angus bulls mated to Angus cows, and (c) F1 bulls mated to 1/4 Nellore 3/4 Angus cows. All cows in the BANH group were produced from mating F1 Bos indicus/Bos taurus bulls to F1 or F2 Bos indicus/Bos taurus cows; this includes cows sired by BA F1 bulls and out of Nellore/Hereford F1 cows as well as cows sired by NA F1 bulls and out of BH F1 or F2 cows (this group includes cows with the various types of reciprocal cross F1 and F2 dams). All females were exposed to bulls as yearlings to give them the opportunity to calve at two years of age. Cows are culled for severe injuries, poor health or at least two failures to have or wean a calf. As the cows reach fourteen years of age, they will be culled for any additional failure to wean a calf, regardless of previous record. All cows in the comparison herds were born in the spring and all calving in the comparison herds is in the spring. To the extent possible, cows of the same breed composition but of different generations (e.g., F1 and F2 cows) were produced with some overlap of ages to allow for a more direct comparison between the groups, but more overlap would have been desirable. PARTICIPANTS: The principle investigator for this project is J.O. Sanders. D.K. Lunt is the superintendent of the McGregor Station, where all the live animal research for the project is conducted. C.A. Gill, A.D. Herring, and D.K. Lunt are co-investigators. J.E. Sawyer and P.K. Riggs are collaborators in the genomics component. T.S. Amen, S.F. Cunningham, R.R. Funkhouser, and C.T. Muntean are graduate students who were involved in conducting the project and received training from the project in 2007. TARGET AUDIENCES: The target audience for this project includes beef cattle producers, extension agents and specialists, and research workers, professors, and students in animal science, animal breeding and genetics, beef cattle production, and quantitative genetics.

Impacts
In one analysis, least squares means for calf crop weaned for B, A, and H cows were .59, .83, and .72, respectively. The value for B is low, because few calve as two year olds. Brahman/Angus and Brahman/Hereford F1 averages were .82 and .82 (reciprocals combined), giving heterosis estimates of .11 and .155. For the reciprocal Brahman/Hereford F1 cows, the F1 HB cows (by Hereford bulls and out of Brahman cows) had higher calf crop weaned (0.88) than the F1 BH (by Brahman bulls and out of Hereford cows) cows (0.79). For the two types of F2 Brahman/Angus cows, those with Angus-sired sires had higher average calf cropped weaned (0.67) than those with Brahman-sired sires (0.59). Note that both of these values are lower than the mid-parent average and considerably lower than would be predicted from the dominance model. There were even larger differences in calf crop weaned among the different types of F2 Brahman/Hereford cows; the F2 cows by HB bulls had higher adjusted mean for calf crop weaned than those by BH bulls. In this analysis, the overall mean for the four types of F2 Brahman/Hereford cows was higher than predicted from the dominance model. From another analysis, adjusted means were 0.57, 0.84, 0.62, and 0.82 for F2 BH (by F1 BH bulls and out of F1 BH females), F2 HB (by F1 HB bulls and out of F1 HB females), F2 BH x HB (by F1 BH bulls and out of F1 HB females), and F2 HB x BH (by F1 HB bulls and out of F1 BH females), respectively. For both the F2 Brahman/Angus and the F2 Brahman/Hereford cows, those with British-sired sires had higher calf crop weaned than those with Brahman-sired sires. The F2 cows by BH bulls were heavier than those by the HB bulls; averaged across all ages, fall cow weights for F2 BH, F2 HB, F2 BH x HB, and F2 HB x BH, were 534, 493, 518, and 477 kg, respectively. In another different analysis, calf crop weaned for B, A, N, and H cows has been .57, .75, .49, and .69, respectively. Again, the values for B and N are low, because few of them calve as two year olds; in addition, the average age of the N cows is less than that of the other breeds, causing their failure to calve as two year olds to have a larger effect on their overall calf crop value. Calf crop weaned for F1 NA, 3N5A, and BANH cows has been .86, .79, and .74, respectively. These values differ from their respective weighted mid-parent means by .24, .14, and .12. Of the 3N5A cows, the heterosis estimate for calf crop weaned for those produced from mating 1/4 Nellore 3/4 Angus bulls to F1 cows (3N5A(a)) was higher than predicted from the dominance model (0.16 vs. 0.12); for those produced from mating 3/4 Nellore 1/4 Angus bulls mated to Angus cows (3N5A(b)) and those produced from mating F1 bulls to 1/4 Nellore 3/4 Angus cows (3N5A(c)), the estimates were less than expected (0.11 vs. 0.18 and 0.03 vs. 0.12, respectively). Adjusted means for fall four year old cow weight for B, A, N, H, F1 NA, 3N5A and BANH were 522, 537, 539, 510, 573, 520, and 537 kg. Weights for the F1 NA, 3N5A and BANH cows differed from their respective weighted mid-parent means by 34, -18, and 10 kg. All three types of 3N5A cows weighed less than the weighted mid-parent mean.

Publications

  • Cunningham, S.F., A.H. Maiga, J.O. Sanders, and A.D. Herring. 2007. Comparison of F1 cows sired by Brahman, Boran, and Tuli for reproductive, maternal, and cow longevity traits. American Society of Ani. Sci., Southern Section Abstracts.
  • Amen , T.S., J.E. Sawyer, A.D. Herring, J.O. Sanders, D.K. Lunt, and C.A. Gill. 2007. Investigation of genetic differences in feed efficiency through comparison of observed vs. predicted feed intake in Bos indicus - Bos taurus F2 full sib steers. American Society of Ani. Sci., National Meeting Abstracts.


Progress 01/01/06 to 12/31/06

Outputs
Breeding herds have been established, starting in 1995, at the McGregor station to evaluate heterosis retention in cattle produced from inter se mating of Bos indicus/Bos taurus crosses. Primary emphasis is on cow productivity. Comparison herds are made up of a minimum of fifty cows each in fourteen different groups. All females in the comparison herds were produced at McGregor. First females for the comparison groups were produced in 1994. The fourteen breeding groups include four purebred groups (Angus (A), Brahman (B), Hereford (H) and Nellore (N)), three F1 groups (Brahman/Angus, Brahman/Hereford and Nellore/Angus (NA)), two F2 groups (Brahman/Angus and Brahman/Hereford), two first-generation groups of 3/8 Bos indicus/5/8 British breeding (3/8 Brahman/5/8 Angus and 3/8 Nellore/5/8 Angus (3N5A)), two second-generation groups of the same 3/8 Bos indicus/5/8 British breed composition and one four-breed crossbred group (BANH, which is 25% of each breed in the purebred groups). Fifty or more females have been produced from all groups. Cows of the fourteen groups will be retained to evaluate lifetime productivity. The Brahman/Hereford F2 group includes all four possible combinations of F1 matings, giving the opportunity to evaluate cows differing in source of X chromosomes and maternal cytoplasm. There were large differences in calf crop weaned among the different types of F2 Brahman/Hereford cows. The F2 cows by Hereford sired (HB) bulls had higher adjusted means for calf crop weaned than those by Brahman sired (BH) bulls. Means were 0.57, 0.84, 0.62, and 0.82 for F2 BH (by F1 BH bulls and out of F1 BH females), F2 HB (by F1 HB bulls and out of F1 HB females), F2 BH x HB (by F1 BH bulls and out of F1 HB females), and F2 HB x BH (by F1 HB bulls and out of F1 BH females), respectively. The F2 cows by BH bulls were heavier than those by the HB bulls; averaged across all ages, fall cow weights for F2 BH, F2 HB, F2 BH x HB, and F2 HB x BH, were 534, 493, 518, and 477 kg, respectively. In a different analysis, calf crop weaned for B, A, N, and H cows has been .57, .75, .49, and .69, respectively. The values for B and N are low because few of them calve as two year olds; in addition, the average age of the N cows is less than that of the other breeds, causing their failure to calve as two year olds to have a larger effect on their overall calf crop value. Calf crop weaned for F1 NA, 3N5A, and BANH cows has been .86, .79, and .74, respectively. These values differ from their respective weighted mid-parent means by .24, .14, and .12. The 3N5A cows were produced from three types of matings, with different mounts of heterosis expected based on the dominance model. For one of the groups, the heterosis estimate was higher than expected from the dominance model; for the other two groups the estimate was less than expected. Adjusted means for fall four year old cow weight for B, A, N, H, F1 NA, 3N5A and BANH were 522, 537, 539, 510, 573, 520, and 537 kg. Weights for the F1 NA, 3N5A and BANH cows differed from their respective weighted mid-parent means by 34, -18, and 10 kg. All three types of 3N5A cows weighed less than their weighted mid-parent mean.

Impacts
Information on heterosis retention in Bos indicus/Bos taurus crosses is needed to design more efficient commercial breeding programs. Results of this study indicate that, in relation to the dominance model, more heterosis than expected is retained in Brahman/Hereford F2s and less heterosis than expected is retained in Brahman/Angus F2s. Results indicate that the 3/8 Nellore 5/8 Angus cows retain about the amount of heterosis expected for reproductive traits but less than expected for weight at four years of age. These differences in the amount of heterosis retained in different crosses may lead to a better understanding of the causes of heterosis. The reciprocal differences in both F1 and F2 crosses for reproductive and mature size characters may lead to an understanding of the reciprocal differences that are found for birth characters.

Publications

  • Amen, T. S., A. D. Herring, J. O. Sanders, and C. A. Gill. 2007. Evaluation of reciprocal differences in Bos indicus x Bos taurus backcross calves produced through embryo transfer: I. Birth and weaning traits. J. Anim. Sci. 85:365-372.
  • Amen, T. S., A. D. Herring, J. O. Sanders, and C. A. Gill. 2007. Evaluation of reciprocal differences in Bos indicus x Bos taurus backcross calves produced through embryo transfer: II. Postweaning, carcass, and meat traits. J. Anim. Sci. 85:373-379.
  • Neufeld Arce, R.O. 2006. Evaluation of heterosis and heterosis retention in Bos taurus-Bos indicus crossbred cattle for reproductive and maternal traits in cows. M.S. Thesis, Texas A&M Univ., College Station.
  • Maiga, A.H. 2006. Comparison of F1 cows sired by Brahman, Boran and Tuli for reproductive, maternal, and cow longevity traits. M.S. Thesis, Texas A&M Univ., College Station.
  • Wright, B.A. 2006. Reciprocal cross differences in Brahman-Hereford F2 cows: reproductive and maternal traits. M.S. Thesis, Texas A&M Univ., College Station.
  • Sanders, J.O., A.D. Herring, D.K. Lunt, J.E. Sawyer, and C.A. Gill. 2006. Investigation of genetic mechanisms influencing disposition in Bos indicus-Bos taurus crossbred cattle. 2006 Beef Cattle Research in Texas. Pp 1-6.


Progress 01/01/05 to 12/31/05

Outputs
Breeding herds have been established, starting in 1995, at the McGregor station to evaluate heterosis retention in cattle produced from inter se mating of Bos indicus/Bos taurus crosses. Primary emphasis is on cow productivity. Comparison herds are made up of a minimum of fifty cows each in fourteen different groups. All females in the comparison herds were produced at McGregor. First females for the comparison groups were produced in 1994. The fourteen breeding groups include four purebred groups (Angus (A), Brahman (B), Hereford (H) and Nellore), three F1 groups (Brahman/Angus, Brahman/Hereford and Nellore/Angus), two F2 groups (Brahman/Angus and Brahman/Hereford), two first-generation groups of 3/8 Bos indicus/5/8 British breeding (3/8 Brahman/5/8 Angus and 3/8 Nellore/5/8 Angus), two second-generation groups of the same 3/8 Bos indicus/5/8 British breed composition and one four-breed crossbred group (25% of each breed in the purebred groups). Fifty or more females have been produced from all groups. Cows of the fourteen groups will be retained to evaluate lifetime productivity. Calf crop weaned for B, A, and H cows has been .59, .83, and .72, respectively. Brahman/Angus and Brahman/Hereford F1 averages have been .82 and .82, giving heterosis estimates of .11 and .155. Reciprocal Brahman/Hereford F1 cows were produced and evaluated; the F1 HB cows (by Hereford bulls and out of Brahman cows) had higher calf crop weaned (0.88) than the F1 BH (by Brahman bulls and out of Hereford cows) cows (0.79). Brahman/Angus and Brahman/Hereford F2 averages have been .64 and .81, giving heterosis estimates in the F2 of -.060 and + .145. The Brahman/Angus F1 cows are all out of Angus cows; the Brahman/Angus F2 cows are all out of Brahman-sired F1 cows, but the sires of these F2 cows included both Brahman-sired (BA) and Angus-sired (AB) F1 bulls. The F2 cows by AB bulls had higher adjusted mean (0.67) for calf crop weaned than those by BA bulls (0.59). The Brahman/Hereford F2 group includes all four possible combinations of F1 matings, giving the opportunity to evaluate cows differing in source of X chromosomes and maternal cytoplasm. There were large differences in calf crop weaned among the different types of F2 Brahman/Hereford cows. Means were 0.61, 0.91, 0.75, and 0.92 for F2 BH (by F1 BH bulls and out of F1 BH females), F2 HB (by F1 HB bulls and out of F1 HB females), F2 BH x HB (by F1 BH bulls and out of F1 HB females), and F2 HB x BH (by F1 HB bulls and out of F1 BH females), respectively. Average cow weight at four yr of age for B, A, and H cows was 505, 519, and 479 kg, respectively. Brahman/Angus and Brahman/Hereford F1 averages were 535 and 524, giving heterosis estimates of 23 and 33 kg. Brahman/Angus and Brahman/Hereford F2 averages were 494 and 534, giving heterosis estimates in the F2 of -18 and +42. There were large differences among the different types of cows within the Brahman/Hereford F2 group; the cows by BH bulls were heavier than those by HB bulls. Adjusted means were 551, 465, 507, and 495 kg for F2 BH, F2 HB, F2 BH x HB, and F2 HB x BH, respectively. These differences are in the opposite direction of those for calf crop weaned.

Impacts
Information on heterosis retention in Bos indicus/Bos taurus crosses is needed to design more efficient commercial breeding programs. The results that indicate that more heterosis is retained in Brahman/Hereford F2s and less heterosis is retained in Brahman/Angus F2s may lead to a better understanding of the causes of heterosis. The reciprocal differences in both F1 and F2 crosses for reproductive and mature size characters may lead to an understanding of the reciprocal differences that are found for birth characters.

Publications

  • Cunningham, S.F. 2005. Evaluation of F1 cows sired by Brahman, Boran, and Tuli for reproductive and maternal performance and cow longevity. M.S. Thesis, Texas A&M Univ., College Station.
  • Cunningham, S.F., Key, K.L., Ducoing, A.E., Sanders, J.O., Herring, A.D. and Lunt, D.K. 2004. Evaluation of F1 cows sired by Brahman, Boran, and Tuli for reproductive and maternal performance and cow longevity. 2005 Beef Cattle Research in Texas. Pp 1-4.
  • Gill, C.A., Amen, T.S., Sanders, J.O. and Herring, A.D. 2005. Reciprocal differences in gestation length and birth weight in Bos indicus/Bos taurus crosses. Proceedings of the Symposium on Tropically Adapted Breeds, American Society of Animal Science Southern Section Meeting, Little Rock, AR, Feb. 8, 2005. Pp 81-86.
  • Herring, A. D., Cunningham, S. F., Cundiff, L. V., Sanders, J. O., Chase, Jr., C. C., Phillips, W. A., Baker, J. F., Holloway, J. W., Warrington, B. G. and Coleman, S. W. 2005. Varying differences between sexes in birth weight and weaning weight of calves sired by tropically adapted breeds at six diverse U.S. locations. Proceedings of the Symposium on Tropically Adapted Breeds, American Society of Animal Science Southern Section Meeting, Little Rock, AR, Feb. 8, 2005. Pp 187-193.
  • Herring, A.D., Sanders, J.O., Lunt, D.K., Sawyer, J.E. Wegenhoft, M.A. and Gill, C.A. 2005. Segregation of disposition scores among families of Bos indicus-Bos taurus crosses. Proc. Western Section Am. Soc. Anim. Sci. 56: 91-94.
  • King, D.A., Morgan, W.W., Miller, R.K., Sanders, J.O., Lunt, D.K., Taylor, J.F., Gill, C.A. and Savell, J.W. 2005. Carcass merit between and among family groups of Bos indicus crossbred steers and heifers. Meat Sci. 72: 496-502.
  • Meuchel, M.C. 2005. Evaluation of heterosis and heterosis retention in Bos taurus - Bos indicus crossbred cattle for productivity traits in cows. M.S. Thesis, Texas A&M Univ., College Station.
  • Sanders, J.O. 2005. Evaluation of heterosis retention for cow productivity traits in Bos indicus / Bos taurus crosses. Proceedings of the 51st Annual Beef Cattle Short Course. Pp H19 - H-28.
  • Sanders, J.O., Riley, D.G., Paschal, J. and Lunt, D.K. 2005. Evaluation of the F1 crosses of five Bos indicus breeds with Hereford for birth, growth, carcass, cow productivity and longevity characteristics. Proceedings of the Symposium on Tropically Adapted Breeds, American Society of Animal Science Southern Section Meeting, Little Rock, AR, Feb. 2005. Pp 94-105.
  • Sanders, J.O., Cunningham, S.F., Ducoing, A., Herring, A.D. and Lunt, D.K. 2005. Evaluation of the F1 crosses of the Tuli, Boran, and Brahman with Hereford and Angus for birth, growth, carcass, cow productivity and longevity characteristics. Proceedings of the Symposium on Tropically Adapted Breeds, American Society of Animal Science Southern Section Meeting, Little Rock, AR, Feb. 8, 2005. Pp 123-127.
  • Sanders, J.O., Key, K.L, Riley, D.G. and Lunt, D.K. 2005. Evaluation of heterosis retention for cow productivity traits in Bos indicus/Bos taurus crosses. Proceedings of the Symposium on Tropically Adapted Breeds, American Society of Animal Science Southern Section Meeting, Little Rock, AR, Feb. 8, 2005. Pp 210-218.
  • Wegenhoft, M.A., Sanders, J.O., Lunt, D.K., Sawyer, J.E., Herring, A.D. and Gill. C.A. 2005. Evaluation of four component traits of disposition in Bos indicus - Bos taurus cross cattle. 2005 Beef Cattle Research in Texas. Pp 5-9.
  • Wright, B.A., Sanders, J.O., Key, K.L., Riley, D.G., and Lunt, D.K. 2005. Evaluation of heterosis retention for cow productivity traits in Bos indicus - Bos taurus crosses. 2005 Beef Cattle Research in Texas. Pp 11-15.


Progress 01/01/04 to 12/31/04

Outputs
Herds have been established at the McGregor station to evaluate heterosis retention in cattle produced from inter se mating of Bos indicus/British crosses; primary emphasis is on cow productivity. Comparison herds will be made up of a minimum of 50 cows each in 14 groups. All these females will be produced at McGregor. First females for the groups were born in 1994. The 14 groups include four purebred groups (Angus (A), Brahman (B), Hereford (H) and Nellore (N)), three F1 groups (BA, BH and NA), two F2 groups (BA and BH), two first-generation 3/8 Bos indicus / 5/8 British groups (3/8 B / 5/8 A and 3/8 N / 5/8 A), two second-generation groups of the same 3/8 / 5/8 composition and one four-breed crossbred group (25% each of A, B, H and N). Fifty or more females have been produced from all groups except the second-generation 3/8 N / 5/8 A. Some females have been produced for all groups. Cows of the 14 groups will be used to evaluate lifetime productivity. Average calf crop born for B, A, and H cows has been .68, .93, and .80, respectively. BA and BH F1 averages have been .90 and .89, giving heterosis estimates of .095 and .15. BA and BH F2 averages have been .74 and .87, giving F2 heterosis estimates of -.065 and + .13. Average calf crop weaned for B, A, and H cows has been .59, .83, and .72, respectively. BA and BH F1 averages have been .82 and .82, giving heterosis estimates of .11 and .155. BA and BH F2 averages have been .64 and .81, giving F2 heterosis estimates of -.060 and + .145. Reciprocal BH F1 calves were produced, allowing estimates of heterosis for calf survival and weaning weight. Survival rates in B and H calves were .79 and .91. Survival rates in H sired calves out B cows and B sired calves out of H cows were .95 and .98, respectively, giving a heterosis estimate of .115 for direct effects on survival. Survival in BH F2 calves (reciprocals combined) was .98. This gives an estimate of .13 for the combination of maternal heterosis plus retained heterosis for direct effects on survival. Weaning weights in B and H calves were 209.4 and 175.6 kg. Weaning weights in H sired calves out B cows and B sired calves out of H cows were 224.8 and 204.2, respectively, giving a heterosis estimate of 22 kg for direct effects. Weaning weight in BH F2 calves (reciprocals combined) was 218.2, giving an estimate of 25.7 kg for the combination of maternal heterosis plus retained heterosis for direct effects. Average cow weight at four yr of age for B, A, and H cows was 505, 519, and 479 kg, respectively. BA and BH F1 averages were 535 and 524, giving heterosis estimates of 23 and 33 kg. BA and BH F2 averages were 494 and 534, giving F2 heterosis estimates of -18 and +42. A genomics study has been initiated with a primary objective of finding genes with major effects on cow fertility and secondary objectives of finding genes with effects on disposition, feed efficiency, and carcass and meat traits. Embryo transfer families of F2 NA calves are being produced, with the goal of 40 calves per family in 10 families. The families are all out of different donor cows and by a total of four bulls. The first calves from this study were born in 2003.

Impacts
Information on heterosis retention in Bos indicus/Bos taurus crosses is needed to design more efficient commercial breeding programs.

Publications

  • Amen, T.S., A.D. Herring, C.A. Gill, and J.O. Sanders. 2004. Investigation of birth weight and gestation length in Bos indicus/Bos taurus cross calves produced through embryo transfer. 2004 Beef Cattle Research in Texas. Pp 1-3.
  • Cunningham, S.F., K.L. Key, A.E. Ducoing, J.O. Sanders, A.D. Herring, and D.K. Lunt. 2004. Evaluation of F1 cows sired by Brahman, Boran, and Tuli for reproductive performance and maternal performance. 2004 Beef Cattle Research in Texas. Pp 5-7.
  • Key, K.L. 2004. Heterosis and heterosis retention for reproductive and maternal traits in Brahman - British crossbred cows. Ph.D. dissertation, Texas A&M University, College Station.
  • Key, K.L., M.C. Meuchel, J.O. Sanders, and D.K. Lunt. 2004. Heterosis retention in Brahman-Angus and Brahman-Hereford F2 cows for reproductive traits and maternal effects on survival and weight traits of their calves. 2004 Beef Cattle Research in Texas. Pp 9-10.
  • Key, K.L., J.O. Sanders, and D.K. Lunt. 2004. Heterosis retention in Brahman-Angus and Brahman-Hereford F2 cows for reproductive traits and maternal effects on survival and weight traits of their calves. American Society of Ani. Sci., Southern Section Abstracts.


Progress 01/01/03 to 12/31/03

Outputs
Breeding herds have been established, starting in 1995, at the McGregor station to evaluate heterosis retention in cattle produced from the inter se mating of Bos indicus/Bos taurus crosses. The primary emphasis in the study is on cow productivity. The comparison herds will be made up of a minimum of fifty cows each in fourteen groups. All females in the comparison herds will be produced at McGregor. The first females for the comparison groups were produced in 1994. The fourteen breeding groups will include four purebred groups (Angus, Brahman, Hereford and Nellore), three F1 groups (Brahman/Angus, Brahman/Hereford and Nellore/Angus), two F2 groups (Brahman/Angus and Brahman/Hereford), two first-generation groups of 3/8 Bos indicus / 5/8 British breeding (3/8 Brahman / 5/8 Angus and 3/8 Nellore / 5/8 Angus), two second-generation groups of the same 3/8 Bos indicus / 5/8 British breed composition and one four-breed crossbred group (25% of each of the breeds in the purebred groups). Fifty or more females have been produced from all groups except the second-generation 3/8 Nellore / 5/8 Angus. Some females have been produced for all groups. Cows of the fourteen groups will be retained to evaluate lifetime cow productivity. Based on preliminary results, there is no strong indication that heterosis retention for cow fertility traits is less than would be expected from degree of expected heterozygosity. Actually, in the Brahman/Hereford crosses, early results indicate as much or more heterosis retention in the F2 than would be predicted based on expected heterozygosity, and, in the Brahman/Angus crosses, less than would be expected. Age and breed group of cow is partially confounded with year in these preliminary results. With these limitations, in the Brahman/Hereford crosses, the heterosis estimate from the F1 for calf crop percent born is 15.8%; the F2 heterosis estimate is 11.6%. In the Brahman/Angus crosses, the F1 heterosis estimate for calf crop percent born is 9.8 percent. The calf crop percent born for the F2 Brahman/Angus crosses has been less (6.4 %) than the average of the straightbreds. Heterosis estimates for calf crop percent weaned are 21.2 and 13.2% for Brahman/Hereford and Brahman/Angus, respectively. In the Brahman/Hereford crosses, the F2 heterosis estimate for calf crop weaned is 14.5%. As for calf crop born, in the Brahman/Angus crosses, the calf crop weaned in the F2 crosses has been less (9.9%) than that of the straightbreds. These results for calf crop percent born are based on the results up through the 2003 calf crop. The results for calf crop percent weaned are based on the results up through the 2002 calf crop. A genomics project has been initiated with the primary objective of finding genes with major effects on cow fertility traits and secondary objectives of finding genes with major effects on disposition, feed efficiency, and carcass and meat traits. Embryo transfer families of F2 Nellore/Angus calves are being produced, with the goal of forty calves per family in ten families. The families are all out of different donor cows and by a total of four bulls. The first calves from this study were born in 2003.

Impacts
Information on heterosis retention in Bos indicus/Bos taurus crosses is needed to design more efficient crossbreeding programs.

Publications

  • Geistweidt, A.R. 2003. Differences among Brahman sires in their offspring in birth, growth and carcass traits. M.S. Thesis, Texas A&M University, College Station.
  • Key, K.L., Ducoing, A.E., Sanders, J.O. and Lunt, D.K. 2003. Evaluation of F1 cows sired by Brahman, Boran, and Tuli for reproductive and maternal performance. 2002 Beef Cattle Research in Texas. Pp 1-3.
  • Key, K.L., Ducoing, A.E., Sanders, J.O. and Lunt, D.K,. 2003. Evaluation of F1 cows sired by Brahman, Boran, and Tuli for reproductive and maternal performance. American Society of Ani. Sci., Southern Section Abstracts.
  • Sanders, J. 2003. Evaluation of tropically adapted breeds for beef cow productivity. Proceedings of the 49th Annual Beef Cattle Shortcourse. Pp I-6 - I-12.


Progress 01/01/02 to 12/31/02

Outputs
Breeding herds have been established, starting in 1995, at the McGregor station to evaluate heterosis retention in cattle produced from the inter se mating of Bos indicus/Bos taurus crosses. The primary emphasis in the study is on cow productivity. The comparison herds will be made up of a minimum of fifty cows each in fourteen groups. All females in the comparison herds will be produced at McGregor. The first females for the comparison groups were produced in 1994. The fourteen breeding groups will include four purebred groups (Angus, Brahman, Hereford and Nellore), three F1 groups (Brahman/Angus, Brahman/Hereford and Nellore/Angus), two F2 groups (Brahman/Angus and Brahman/Hereford), two first-generation groups of 3/8 Bos indicus / 5/8 British breeding (3/8 Brahman / 5/8 Angus and 3/8 Nellore / 5/8 Angus), two second-generation groups of the same 3/8 Bos indicus / 5/8 British breed composition and one four-breed crossbred group (25% of each of the breeds in the purebred groups). Fifty or more females have been produced from all groups except the purebred Nellore and the second-generation 3/8 Nellore / 5/8 Angus. Some females have been produced for all groups. Cows of the fourteen groups will be retained to evaluate lifetime cow productivity. Based on preliminary results, there is no strong indication that heterosis retention for cow fertility traits is less than would be expected from degree of expected heterozygosity. Actually, in the Brahman/Hereford crosses, early results indicate as much or more heterosis retention in the F2 than would be predicted based on expected heterozygosity, and, in the Brahman/Angus crosses, less than would be expected. Age and breed group of cow is confounded with year in these preliminary results. With these limitations, in the Brahman/Hereford crosses, the heterosis estimate from the F1 for calf crop percent born is 11%; the F2 heterosis estimate is 7%. In the Brahman/Angus crosses, the F1 heterosis estimate for calf crop percent born is less than one percent (.002). The calf crop percent born for the F2 Brahman/Angus crosses has been less (5 %) than the average of the straightbreds. Heterosis estimates for calf crop percent weaned are 10 and 2% for Brahman/Hereford and Brahman/Angus, respectively. In the Brahman/Hereford crosses, the F2 heterosis estimate for calf crop weaned is 5%. However, in the Brahman/Angus crosses, the calf crop weaned in the F2 crosses has been slightly less than that of the straightbreds. These results for calf crop percent born are based on the results up through the 2002 calf crop. The results for calf crop percent weaned are based on the results up through the 2001 calf crop. Up through the 2001 calf crop, heterosis for calf survival was 8 and 7 %, respectively, in the Brahman/Hereford and Brahman/Angus F1 crosses (survival of calves out of the F1cows). In the Brahman/Hereford crosses, the F2 heterosis estimate for calf survival is slightly less than 8% (94% of the estimate of F1 heterosis). As was the case for calf crop percent weaned, calf survival for calves out of the F2 Brahman/Angus cows has been slightly lower than that out of the straightbred cows.

Impacts
Information on heterosis retention in Bos indicus/Bos taurus crosses is needed to design more efficient crossbreeding programs.

Publications

  • Ducoing, A.E. 2002. Evaluation of F1 cows sired by Brahman, Boran and Tuli bulls for reproductive and maternal performance. Ph.D. dissertation, Texas A&M University, College Station.
  • Bartel, Harry Fehr. 2002. Differences among Beefmaster sires in their offspring in birth, growth and carcass traits. M.S. Thesis, Texas A&M University, College Station.


Progress 01/01/01 to 12/31/01

Outputs
Cows out of Hereford and Angus dams and by Tuli, Boran and Brahman bulls have been evaluated since 1994. Average weights as seven-year-olds were 485, 488 and 575 kg for the Tuli-, Boran- and Brahman-sired cows, respectively. Across all ages of dams, from two to nine years, average weaning weights for calves out of Tuli-, Boran- and Brahman-sired cows were 200, 215 and 230 kg, respectively. Calf crop percentages born for Tuli-, Boran- and Brahman-sired cows were 89.0, 92.7 and 86.3, respectively. Calf survival percentages for calves out of Tuli-, Boran- and Brahman-sired cows were 93.9, 95.2 and 93.9, respectively. Calf crop weaned percentages for the Tuli-, Boran- and Brahman-sired cows were 83.7, 87.4 and 80.8, respectively. Breeding herds are being established at the McGregor station to evaluate heterosis retention in cattle produced from the inter se mating of Bos indicus/Bos taurus crossbreds. The primary emphasis in the study is on cow productivity traits. The comparison herds will be made up of a minimum of fifty cows each in fourteen different groups. All females in the comparison herds will be produced at McGregor. The first females for the comparison groups were produced in 1994. The fourteen breeding groups will include four purebred groups (Angus, Brahman, Hereford and Nellore), three F1 groups (Brahman/Angus, Brahman/Hereford and Nellore/Angus), two F2 groups (Brahman/Angus and Brahman/Hereford), two first-generation groups of 3/8 Bos indicus / 5/8 British breeding (3/8 Brahman / 5/8 Angus and 3/8 Nellore / 5/8 Angus), two second-generation groups of the same 3/8 Bos indicus / 5/8 British breed composition and one four-breed crossbred group (25% of each of the breeds in the purebred groups). Fifty or more females have been produced from all of the groups except the purebred Nellore and the second-generation 3/8 Nellore / 5/8 Angus. Some females have been produced for all of the groups except for the second-generation 3/8 Nellore / 5/8 Angus; the first calves of this cross will be born in 2002. Cows of the fourteen groups will be retained to evaluate lifetime cow productivity.

Impacts
Information on the productivity of Tuli-, and Boran-crossbred cows is very limited. By comparing their productivity to that of Brahman-Hereford and Brahman-Angus F1 cows, decisions can be made about the utility of the Tuli and Boran for the US beef industry. Information on heterosis retention in Bos indicus/Bos taurus crosses is needed to design more efficient crossbreeding programs.

Publications

  • Riley, D.G., J.O. Sanders, R.E. Knutson and D.K. Lunt. 2001. Comparison of F1 Bos indicus X Hereford cows in Central Texas. I. Reproductive, maternal and size traits. J. Anim. Sci.79:1431-1438.
  • Riley, D.G., J.O. Sanders, R.E. Knutson and D.K. Lunt. 2001. Comparison of F1 Bos indicus X Hereford cows in Central Texas. II. Udder, mouth, longevity and lifetime productivity. J. Anim. Sci.79:1439-1449.
  • Ducoing, A.E. and J.O. Sanders. 2001. Evaluation of F1 cows sired by Brahman, Boran, and Tuli bulls for birth and weaning weight, calf crop born, calf survival and calf crop weaned. American Society of Ani. Sci., Southern Section Abstracts, p.6.


Progress 01/01/00 to 12/31/00

Outputs
Cows out of Hereford dams and by Angus (A, n=10), Gray Brahman (B, n = 11), Gir (G, n=6), Indu-Brazil (I, n=10), Nellore (N, n=10) and Red Brahman (R, n=10) bulls have been evaluated since 1985. Initially, there were 15 A-, 21 B-, 15 G-, 19 I-, 25 N- and 21 R-sired cows. One A-, two B-, five G-, no I-, ten N_ and two R-sired cows remain in the project. Until about 12 years of age, cows were generally culled if they were diagnosed as open by rectal palpation and had failed to wean a calf in the current or any previous year. After about 12 years of age, cows were culled if diagnosed as open or if they failed to wean a calf, without regard to previous record. Within a given year, all cows were bred to the same bulls. Calves have been produced from 1985 to 2000. Average birth weight in calves out of A-sired cows was 39.4 kg; in calves out of the Bos indicus cross cows, average birth weight ranged from 34.8 kg for G-sired cows to 37.2 kg in both I- and R-sired cows. Average weaning weight in calves out of A-sired cows was 227 kg; in calves out of the Bos indicus cross cows, average weaning weight ranged from 256 kg for both G- and I-sired cows to 261 kg in R-sired cows. Average mature weights for the A-, B-, G-, I-. N- and R-sired cows were 521, 586, 538, 572, 550 and 578 kg, respectively. Calf crop born percentages for the A-, B-, G-, I-. N- and R-sired cows were 87, 96, 95, 93, 97 and 93, respectively. Calf crop weaned percentages were 83, 88, 92, 81, 96 and 86, respectively. Survival rates of the different types of crossbred cows to 14 years of age were evaluated under the actual and three different imposed culling policies. Under the actual culling policy, the least squares means for the percentages of cows that survived to 14 years of age were 53, 53, 73, 33, 80 and 43 for the A-, B-, G-, I-, N- and R-sired cows, respectively. Under the imposed policy, where a cow was removed after the first time that she failed to wean a calf, the corresponding percentages were 21, 18, 40, 19, 54 and 14, respectively. As with these two policies, for the other two imposed policies, Nellore crosses had the highest survival rates and Gir crosses had the next highest rates. Under the actual culling policy, the least squares means for the age of cows at removal from the project were 12.4, 12.3, 13.8, 11.9, 13.7 and 12.3 years for the A-, B-, G-, I-, N- and R-sired cows, respectively. Under the imposed policy, where a cow was removed after the first time that she failed to wean a calf, the corresponding ages were 6.9, 6.7, 9.4, 8.9, 10.8 and 8.1 years, respectively. For the other two imposed policies, Nellore crosses had the highest age at removal and Gir crosses had the next highest age.

Impacts
Information on the productivity of Nellore-, Gir- and Indu-Brazil-crossbred cows is very limited. By comparing their productivity to that of Angus-Hereford and Brahman-Hereford F1's, decisions can be made on the utility of these breeds for the US beef industry.

Publications

  • Riley, D.G. 2000. Heterosis and heterosis retention in reproductive traits, weight and condition of Brahman-British crossbred cows. Ph.D. dissertation.
  • Riley, D. G., Hager, L. B., Sanders, J. O., Miller, R. K. and Lunt, D. K. 2000. Comparison of Warner-Bratzler shears of F1 Bos indicus / British steers produced by one Nellore and 15 Brahman bulls. J. Anim. Sci. 78 (Suppl. 1) :59 (Abstr.).


Progress 01/01/99 to 12/31/99

Outputs
Breeding herds are being established at the McGregor station to evaluate heterosis retention in cattle produced by the inter se mating of Bos indicus / Bos taurus crossbreds. The primary emphasis in the study is on cow productivity traits. The comparison herds will be made up of a minimum of 50 cows each in 14 different groups. All females in the comparison herds will be produced at McGregor. The first females for the comparison groups were produced in 1994. The 14 breeding groups will include four purebred groups (Angus, Brahman, Hereford and Nellore), three F1 groups (Brahman/Angus, Brahman/Hereford and Nellore/Angus), two F2 groups (Brahman/Angus and Brahman/Hereford), two first generation groups of 3/8 Bos indicus / 5/8 British breeding (3/8 Brahman / 5/8 Angus and 3/8 Nellore / 5/8 Angus), two second generation groups of the same 3/8 Bos indicus / 5/8 British breed composition, and one four-breed crossbred group (25% each of the four breeds in the purebred groups). Fifty or more females have been produced for all of the groups except the purebred Nellore, the first and second generation 3/8 Nellore / 5/8 Angus, the second generation 3/8 Brahman / 5/8 Angus and the four breed group. Some females have been produced for all of the groups except the second generation 3/8 Nellore / 5/8 Angus group. Cows of the fourteen groups will be retained to evaluate lifetime cow productivity. Results from Australia have indicated more heterosis loss from the F1 to the F2 female than the fifty percent that is predicted from the dominance model for cow fertility traits. Although generation of cow is partially confounded with year and with age of cow, preliminary results from this study indicate less heterosis loss than predicted from the dominance model for pregnancy rate. In fact, pregnancy rates have been as high for the F2s as for the F1s in both the Brahman / Angus and the Brahman / Hereford comparisons. Average pregnancy rate for the F1 Brahman / Angus has been .81, and for the F2 the average has been .85. For the F1 Brahman / Hereford, average pregnancy rate has been .77 vs .78 in the F2 Brahman / Hereford females.

Impacts
The productivity of the F1 Bos indicus / British female is well documented, but these F1 females are expensive to produce, because of lower fertility and higher levels of dystocia in the purebred dams. Advanced generation crossbreds, including the F2, are less expensive to produce, but inadequate information is available about their productivity. This study is designed to provide this information.

Publications

  • Riley, D.G. and J.O. Sanders. 1999. Heterogeneity of estimated variance for birth weight in Bos indicus and British cattle and their crosses. J. Anim. Sci. 77 (Supplement 1):4.


Progress 01/01/98 to 12/31/98

Outputs
Breeding herds are being established at the McGregor station to evaluate heterosis retention in cattle produced by inter se mating of Bos indicus / Bos taurus crossbred cattle. The emphasis in the study is on cow productivity traits. The comparison herds will be made up of a minimum of 50 cows in each of 14 different groups. All females in the comparison herds will be produced at McGregor. The first females for the comparison groups were produced in 1994. The 14 breeding groups will include 4 purebred groups (Angus, Brahman, Hereford and Nellore), three F1 groups (Brahman/Angus, Brahman/Hereford and Nellore/Angus), two F2 groups (Brahman/Angus and Brahman/Hereford), two first generation groups of 3/8 Bos indicus / 5/8 British breeding (3/8 Brahman / 5/8 Angus and 3/8 Nellore / 5/8 Angus), two second generation groups of the same 3/8 Bos indicus / 5/8 British breed composition, and one four-breed crossbred group (25% each of the 4 breeds in the purebred groups). Fifty or more females have been produced for the Angus, Hereford, all three F1 groups, both F2 groups and the first generation 3/8 Brahman / 5/8 Angus group. Some females have now been produced for all of the other groups except the second generation 3/8 Nellore / 5/8 Angus group. Cows of the fourteen groups will be retained to evaluate lifetime cow productivity. Cows out of Hereford dams and by Angus, Gray Brahman, Gir, Indu Brazil, Nellore and Red Brahman bulls have been evaluated since 1985. Initially, there were 115 females, and 52 remain in the study. Cows had been culled when they could no longer raise a calf or when they failed to calve in two consecutive years. After they reached twelve years of age, cows have been culled if they fail to calve, without regard to previous records. Of the original females, 33, 43, 53, 21, 76 and 33 % of the cows by the respective breeds of sire remain in the study. Calf crop percentages weaned have averaged 84, 88, 91, 85, 95 and 87, respectively. Average weaning weights for calves out of cows of the six different crosses have been 218, 248, 246, 246, 247 and 250 kg, respectively. Average cow weights in the fall, when their calves are weaned, have been 498, 557, 514, 547, 522 and 543 kg, respectively. Cows out of both Hereford and Angus dams and by Tuli, Boran and Brahman bulls have been evaluated since 1994. Calf crop percentages weaned have averaged 78, 83 and 73 for cows sired by Tuli, Boran and Brahman bulls, respectively. Cow weights in the fall, when their calves are weaned, have averaged 456, 465 and 514 kg, respectively. Weaning weights for calves out of dams of these three types have averaged 190, 201 and 217 kg, respectively.

Impacts
(N/A)

Publications

  • Riley, D.G., Sanders, J.O. and Lunt, D.K. 1998. Cow productivity in Brahman-Hereford F1's compared to other F1 Bos indicus-Hereford crosses. American Society of Animal Science, Southern Section Abstracts, p. 4.
  • Riley, D.G., Sanders, J.O. and Knutson,R.E. 1998. Cow production traits in Brahman-British F1's compared to F1 crosses of two African breeds with Hereford and Angus. American Society of Animal Science, Southern Section Abstracts, p. 5.


Progress 01/01/97 to 12/31/97

Outputs
Cows out of Hereford dams and sired by bulls of the Angus, Gray Brahman, Gir, Indu Brazil, Nellore and Red Brahman breeds have been evaluated since 1985. Initially, there were 115 F1 females, and 87 remain in the project. Cows have been culled when they can no longer raise a calf or when they fail to calve in two consecutive years. Udder measurements and scores have been recorded shortly after calving each year. Average teat lengths by these breeds of sires have been 5.7, 5.7, 5.3, 7.2, 4.7 and 5.1 cm, respectively. Average teat diameters have been 2.5, 2.6, 2.5, 3.1, 2.2 and 2.6 cm, respectively. Udder support scores, where a lower score is more pendulous, have been 4.9, 4.9, 4.8, 4.3, 5.2 and 4.7, respectively. Calf crop percentages born have averaged 90, 96, 96, 95, 97 and 94. Calf crop percentages weaned have averaged 85, 89, 92, 89, 95 and 88 . Average birth weights for calves out of these cors have been 39.6, 37.5, 34.9, 37.3, 37.1 and 37.6 kg. Average weaning weights have been 225, 255, 251, 251, 253 and 257 kg.

Impacts
(N/A)

Publications

  • Riley,D.G. 1997. Evaluation of postpartum udder characteristics of F1 cows sired by Angus, Gray Brahman, Gir, Indu Brazil, Nellore and Red Brahman bulls. M.S. thesis, Texas A&M Univ., College Station.
  • Kuykendall, J.W. 1997. Evaluation of birth, weaning and carcass traits of F1 calves sired by Brahman bulls. M.S. thesis, Texas A&M Univ., College Station.


Progress 01/01/96 to 12/30/96

Outputs
Cows out of Hereford dams and sired by bulls of the Angus, Gray Brahman, Gir, Indu Brazil and Nellore breeds have been evaluated since 1985. Initially, there were 115 F1 females, and 80 remain in the project. Cows have been culled when they can no longer raise a calf or when they fail to calve in two consecutive years. Udder measurements and scores have been recorded shortly after calving each year. Average teat lengths by these breeds of sire have been 5.8, 5.7, 5.3, 7.2, 4.7 and 5.1 cm, respectively. Average teat diameters have been 2.5, 2.6, 2.5, 3.1, 2.2 and 2.6 cm, respectively. Udder support score averages, where a lower score is a more pendulous udder, have been 4.9, 4.9, 4.8, 4.3, 5.2 and 4.7, respectively. Calf crop percentages born have averaged 89, 97, 96, 95, 96 and 95, respectively. Calf crop percentages weaned have averaged 83, 89, 92, 89, 95 and 89, respectively. Average weaning weights of calves out of these cows have been 233, 263, 259, 259, and 260 kg, respectively.

Impacts
(N/A)

Publications

  • Riley, D.G., Kleibrink, K.M., Sanders, J.O. and Lunt, D.K. 1996. Udder characteristics of F1 cows sired by Angus, Gray Brahman, Gir, Indu-Brazil, Nellore and Red Brahman and preweaning growth of their calves. J. Anim. Sci. 74(Suppl. 1):125.


Progress 01/01/95 to 12/30/95

Outputs
Cows born from 1982-1985 have been evaluted since 1985. Cows are F1's out of Hereford dams and sired by Angus or five different Zebu breeds. Initially, there were 115 F1 females. Cows have been culled when they can no longer raise a calf or fail to calve in two consecutive years. Currently, 89 cows remain in the project. Calf crop percentages born for Angus-, Gray Brahman-, InduBrazil-, Nellore- and Red Brahman-sired females have averaged 89.0, 96.5, 95.7, 94.9, 96.3 and 94.9. Percentages weaned have averaged 82.7, 89.4, 92.2, 89.1, 95.4 and 89.3. Calves have been sired by Charolais, Salers, Angus, Brangus and/or Simmental bulls, depending on the year. Average birth weight for calves out of the above types of F1 cows have been 40.7, 38.6, 35.9, 38.1, 37.8 and 38.5 kg. In the F1 phase, average birth weights for the F1 calves were 31.8, 37.1, 33.0, 39.1, 36.7 and 37.4 kg., respectively. For a pair of breeds, the maternal effects (plus half the difference of maternal heterosis) can be estimated by subtracting half the difference between two types of F1 calves form the difference between the calves out of the same two types of F1 cows. These results indicate a maternal difference between Angus and Gray Brahman of 4.75 kg, consistent with results from reciprocal F1 crosses. Results of this study indicate a larger negative effect of the other four Zebu breeds than the Gray Brahman with the largest negative effect in the Gir.

Impacts
(N/A)

Publications

  • Rohrer, G.A., Taylor, J.F., Sanders, J.O. and Thallman, R.M. 1994. Evaluation of line and breed of cytoplasm on performance of purebred Brangus cattle. J.Anim. Sci. 72:2798.
  • Herring, K.L. 1995. Mapping of genes using BAC library to determine their effects on economically important traits in cattle, M.S. Thesis, TAMU, College Station, TX.
  • Paschal, J.C., Sanders, J.O., Kerr, J.L., Lunt,D.K. and Herring, A.D. 1994. Postweaning and feedlot growth and carcass characteristics of Angus-,Gray Brahman-, Gir-, Indu-Brazil, Nellore-, and Red Brahman-sired F1 calves. J.Anim. Sci. 73:37
  • May, S.G., Burney, N.S., Wilson, J.J., Savell, J.W., Herring, A.D., Lunt, D.K., Baker, J.F., Sanders, J.O. and Smith, S.B. 1995. Lipogenic activity of intramuscular and subcutaneous adipose tissue from steers produced by different generatio
  • Herring, A.D., Sanders, J.O., Knutson, R.E. and Lunt, D.K. 1995. Evaluation of F1 calves sired by Brahman, Boran and Tuli bulls for birth, growth, size and carcass characteristics. J. ANim. Sci. (In press).


Progress 01/01/94 to 12/30/94

Outputs
Cows born from 1982-1985, have been evaluated for productivity since 1985. All cows are F1's out of Hereford dams and sired by Angus or five different Zebu breeds. Initially, there were 115 F1 females. Cows have been culled only when they could no longer raise a calf and/or when they fail to calve in two consecutive years. Currently, 95 cows remain in the project. In calves born from 1985 to 1993, calf crop percentages born for Angus-, Gray Brahman-, Gir-, Indu Brazil-, Nellore- and Red Brahman-sired F1 females have averaged 88.6, 95.7, 96.3, 96.0, 95.9 and 95.1, respectively. Calf crop percentages weaned have averaged 77.4, 86.3, 90.5, 91.0, 94.6 and 88.6, respectively. Calves have been sired by Charolais, Salers and/or Angus bulls, depending on the year, with cows randomly assigned to breed of sire. Average birth weights for calves out of the above respective types of F1 cows have been 41.5, 39.1, 37.0, 38.2, 38.2 and 38.6 kg, respectively. Average weaning weights have been 233.8, 268.0, 266.4, 263.6, 266.9 and 271.1 kg, respectively. In a separate study, F1 females out of either Angus or Hereford dams and sired by Tuli, Boran or Brahman bulls were born in 1992 and 1993 and are currently being evaluated for cow productivity traits. For the two years combined, 96.1% of the Tuli crosses, 94.4% of the Boran crosses and 82.1% of the Brahman cross heifers conceived as yearlings to calve as two year olds. For the two year olds, born in 1992, 36.4% of the Tuli crosses, 68.4% of the Boran crosses and 44.

Impacts
(N/A)

Publications

  • FISHER, N.S., HERRING, A.D., SANDERS, J.O., LUNT, D.K. and KNUTSON, R.E. 1993. Cow productivity of F1 Bos indicus females sired by five different Zebu breeds. Beef Cattle Research in Texas. TAES Tech. Rpt. PR5153-5210:7-9.
  • MAY, S.G., WILSON, J.J., SAVELL, J.W., LUNT, D.K., BAKER, J.F., SANDERS, J.O. and SMITH, S.B. 1994. Lipogenic activity of intramuscular and subcutaneous adipose tissues from steers produced by different generations of Angus sires. J. Anim.


Progress 01/01/93 to 12/30/93

Outputs
In calves born from 1985 to 1992, F(subscript 1) Zebu-Hereford cows had higher calf crop percentages born (96.1 to 96.0 for five different Zebu breeds) and weaned (86.3 to 94.6%) than F(subscript 1) Angus-Hereford cows (87.1 and 77.4%). Calf crop percentage born and weaned was highest for the F(subscript 1) Nellore-Hereford cows (96.0 and 94.6%). The Indu Brazil, Gir, Red Brahman and Gray Brahman-sired F(subscript 1) cows differed only slightly from the Nellore crosses and from each other for calf crop percentage born (95.1 to 95.8%) but differed more for calf crop percentage weaned (91.0, 90.5, 88.6 and 86.3%, respectively). Calves were sired by Charolais, Salers and/or Angus bulls depending on the year with cows randomly assigned to breed of sire. Calves were significantly lighter at birth out of the Zebu-sired cows compared to those out of the F(subscript 1) Angus-Hereford cows. Among the Zebu crosses, calves out of Gir-sired cows were the lightest (36.7 kg) and those out of Gray Brahman sired cows were the heaviest (39.0 kg). Average weaning weights and hip heights were higher for calves out of all five types of Zebu-sired females than for those out of Angus-sired cows. Among the Zebu-sired females, Red Brahman crosses weaned the heaviest calves (268 kg) and Indu Brazil crosses weaned the lightest calves (260 kg). Udders were evaluated shortly after calving for all cows in all years. Measurements were estimates based on visual examination at close range.

Impacts
(N/A)

Publications

  • FISHER, N.S., SANDERS, J.O. and KNUTSON, R.E. 1993. Evaluation of productivity and reproductive efficiency of F(subscript 1) Bos indicus females sired by five Zebu breeds. J.Anim. Sci. 71 (Suppl. 1): 105.


Progress 01/01/92 to 12/30/92

Outputs
From records of 691 Simmental-Brahman F(subscript 1) calves produced by embryo transfer, those sired by Brahman bulls and out of Simmental donors had 1.96 d longer gestation, 10.7 kg heavier birth weight and 35.1 kg heavier weaning weight averages than those by Simmental bulls and out of Brahman donors. Embryos were assigned to Holstein or crossbred beef recipient cows at random. Differences between Brahman sired and Simmental sired F(subscript 1) calves were approximately twice as large in bull calves as in heifer calves. In calves born from 1985 to 1992, F(subscript 1) Zebu-Hereford cows had higher calf crop percentages born (95.0 to 95.9 percent for five different Zebu breeds) than F(subscript 1) Angus-Hereford cows (85.6%). In calves born from 1985-1991 the calf crop percentage weaned was highest for F(subscript 1) Nellore-Hereford cows (92.7%), followed by Indu Brazil, Red Brahman, Gray Brahman, Angus and Gir sired cows (90.4, 88.1, 85.4, 83.1 and 81.4%, respectively). Calves were sired by Charolais, Salers and/or Angus bulls, depending on the year, with cows randomly assigned to breed of sire. Birth weight averages were lower for calves out of all of the Zebu-Hereford F(subscript 1)'s (36.7, 38.0, 38.1, 38.1 and 39.0 kg for the Gir, Nellore, Indu Brazil, Red Brahman and Gray Brahman cross cows, respectively) than those out of Angus-Hereford cows (41.5 kg). Weaning weights were higher for calves out of the Zebu cross cows (263.5, 260.6, 258.1, 256.6 and 254.

Impacts
(N/A)

Publications

  • THALLMAN, R.M., TAYLOR, J.F., SANDERS, J.O. and QUAAS, R.L. 1992. Non-traditional genetic effects in reciprocal cross Brahman X Simmental F(subscript 1) calves produced by embryo transfer. J. Anim. Sci. 70(Suppl. 1):140 (Abstract).
  • HERRING, A.D., SANDERS, J.O. and KNUTSON, R.E. 1992. Evaluation of reproductive efficiency and productivity of F(subscript 1) Bos indicus females sired by five Zebu breeds. McGregor Field Day Report. TAES Tech. Rpt. 92-1:34-39.
  • ROCHA, J.L., BAKER, J.F., WOMACK, J.E., SANDERS, J.O. and TAYLOR, J.F. 1992. Statistical associations between restriction fragment length polymorphisms and quantitative traits in beef cattle. J. Anim. Sci. 70:3360.
  • SACCO, R.E., BAKER, J.F., CARTWRIGHT, T.C., LONG, C.R. and SANDERS, J.O. 1991. Heterosis retention for birth and weaning characters of calves in the third generation of a five breed diallel. J. Anim. Sci. 69:4754.


Progress 01/01/91 to 12/30/91

Outputs
From records of approximately 1500 naturally produced and 2300 embryo transfer Brangus males, species of origin of Y chromosome, Bos taurus vs Bos indicus, was concluded not to have a significant effect on growth traits, scrotal circumference, sheath score, or occurrence of extended prepuce. Phenotypic correlations of sheath score and growth traits were low (<.10). Phenotypic correlation between sheath score and occurrence of extended prepuce was low at weaning (.15) but much higher in yearling evaluations (.41); phenotypic correlation between weaning and yearling sheath score was approximately 0.6. From records on 677 animals produced in a five breed diallel of Angus(A), Brahman(B), Hereford(H), Holstein and Jersey, two potentially useful associations between production traits and genotypes for restriction fragment length polymorphisms were detected, following three different analytical designs. Three Growth Hormone-TaqI alleles (B,C,D), in high frequencies in this sample of the Brahman breed, were associated with decreases in birth weight, as a maternal trait (P<.01). Among F(subscript 2) A-B and H-B cows, homozygotes for these alleles (B,C,D) produced calves that were 4.0 kg lighter at birth than AA homozygotes, with no effect on weights at later ages. A maternal grandam effect (corresponding to source of cytoplasm) appears to interact (P=.03) with this maternal effect on birth weight.

Impacts
(N/A)

Publications

  • HERRING, A.D. and SANDERS, J.O. 1991. Evaluation of performance, sheath score and scrotal circumference of Brangus bulls based on the species of Y chromosome origin. J. Anim. Sci. 69 (Suppl. 1):208.
  • ROCHA, J.L., BAKER, J.F., WOMACK, J.E., SANDERS, J.O. and TAYLOR, J.F. 1991. Association between RFLPs and quantitative traits in beef cattle. J. Anim. Sci. 69(Suppl. 1):201.
  • LOTT, B.R., SANDERS, J.O., LUNT, D.K. and BAKER, J.F. 1991. Effect of Angus, Charolais and Salers sires on birth, weaning and carcass traits of calves. J. Anim. Sci. 69(Suppl. 1):197.


Progress 01/01/90 to 12/30/90

Outputs
Of 373 exposures to breeding in F(1) females, Indu-Brazil-Hereford and Nellore-Hereford crosses weaned higher calf crop percentages (93 and 92) than crosses of Gir, Gray Brahman, Red Brahman and Angus with Hereford (89, 83, 83 and 75%, respectively). Calves out of these F(1) cows and by Charolais bulls were 2 kg heavier at birth and 7 kg heavier at weaning than those by Salers bulls. Carcass characteristics were similar for the two sire breeds. In 97 calvings out of Simmental cows, calves by modern Angus bulls were larger at all ages than those by Angus bulls available prior to 1971. Average birth weights were 40.7 and 35.5 kg, weaning weights were 251 and 219 kg and carcass weights were 343 and 310 kg, respectively. Carcass fat thickness, ribeye area and marbling scores were similar for the two groups; heavier carcasses of those by the modern bulls resulted in higher yield grades. In 329 calvings of cows of the Angus, Brahman, Hereford, Holstein and Jersey breeds and their crosses, calves by Charolais and Salers bulls were only slightly larger at birth and weaning than those by Angus bulls. For Charolais, Salers and Angus sired calves, average birth weights were 34.7, 34.5 and 34.1 kg and weaning weights were 231, 225 and 225 kg, respectively. Postweaning growth was less than expected in the Charolais crosses, resulting in lower carcass weights than for the other two sire breeds; however, ribeye area for the Charolais crosses was similar to that of Salers crosses and larger than for Angus crosses.

Impacts
(N/A)

Publications

  • ZIEHE, G.K. and SANDERS, J.O. 1990. Udder characteristics of F(1) females by five breeds of Zebu sires. J. Anim. Sci. 68 (Suppl. 1):235.
  • THALLMAN, R.M., SANDERS, J.O. and TAYLOR, J.F. 1990. Prediction of genetic values for weaning weight from field data on calves produced by embryo transfer. J. Anim. Sci. 68 (Suppl. 1):252.
  • ROHRER, G.A., TAYLOR, J.F., SANDERS, J.O. and THALLMAN, R.M. 1990. Recipient cow effects on Brangus calves produced by embryo transfer. J. Anim. Sci. 68 (Suppl. 1):252.
  • LUNT, D.K., SMITH, G.C., RILEY, R.R., PELTON, L.S., CROSS, H.R. and SANDERS, J.O. 1990. Growth and carcass traits of crossbred Wagyu steer calves and yearlings when fed to a constant fat thickness. J. Anim. Sci. 68 (Suppl. 1):349.
  • HERRING, A.D., SANDERS, J.O. and LUNT, D.K. 1990. Comparison of Charolais and Salers as terminal sire breeds. McGregor Field Day Report. TAES Tech. Rpt. 90-1:63-65.
  • LOTT, B.R., SANDERS, J.O., LUNT, D.K. and BAKER, J.F. 1990. Comparison of birth and carcass characters of calves sired by Angus, Charolais or Salers. McGregor Field Day Report. TAES Tech Rpt. 90-1:66-70.
  • RUFFIN, T.D., SANDERS, J.O., LUNT, D.K. and BAKER, J.F. 1990. Progress report on the evaluation of differences in birth, growth and carcass characters of offspring of Angus sires available prior to 1970 and those born since 1985.


Progress 01/01/89 to 12/30/89

Outputs
In 346 calvings out of 115 Fl females, Nellore-Hereford cross cows had shorter and smaller diameter teats (3.97 and 1.78 cm, respectively, in first parity) and Indu Brazil-Hereford crosses had longer and larger diameter teats (5.37 and 2.37 cm in first parity) than crosses of Gray Brahman, Gir and Red Brahman with Hereford; Angus-Hereford crosses had averages of 5.75 and 2.12 cm, respectively. Nellore crosses and Indu Brazil crosses, respectively, had the highest and lowest (most pedulous) udder support scores in the fourth parity data. Indu Brazil cross cows have also had the highest incidence of calves requiring assistance in nursing due to udder unsoundness. Calves out of the Gir cross cows were lightest at birth (33.2 kg); among the Zebu cross cows, Gray Brahman crosses had the heaviest calves (37.2 kg) which were similar in birth weight to those out of Angus-Hereford cross cows (37.3 kg). Charolais sired calves (n = 262) were 1.7 kg heavier at birth than Salers sired calves (n = 89). Based on 221 records, calves out of Red Brahman cross and Gray Brahman cross cows were heaviest at weaning (255.1 and 251.9 kg, respectively); calves out of Nellore, Gir and Indu Brazil sired cows had average weaning weights of 246.7, 243.5 and 243.3 and were heavier than those out of Angus sired cows (221.4 kg). Charolais sired calves (n = 185) were 7 kg heavier than Salers sired calves (n = 36). Based on one calf crop, carcasses from Charolais crosses were leaner YG = 2.2 vs 2.

Impacts
(N/A)

Publications

  • ZIEHE, G.K. 1989. Evaluation of udder and teat characteristics of Fl females by Angus, Gray Brahman, Gir, Indu Brazil, Nellore and Red Brahman sires. M.S. Thesis, Texas A&M Univ., College Station. 68 p.
  • ELIZONDO, E.B. 1989. Evaluation of five Zebu breeds for cow productivity. M.S. Thesis. 70 p.
  • ZIEHE, G.K., SANDERS, J.O. and ELIZONDO, E.B. 1989. Udder characteristics of first parity Fl females sired by Angus, Gray Brahman, Gir, Indu-Brazil, Nellore and Red Brahman sires. J. Anim. Sci. 67(Suppl. 1):91 (Abstract).
  • PASCHAL, J.C. and SANDERS, J.O. 1989. Calving and weaning characteristics of Fl calves sired by Angus, Gray Brahman, Gir Indu-Brazil, Nellore and Red Brahman sires. J. Anim. Sci. 67(Suppl. 1): 91 (Abstract).
  • LUNT, D.K., SANDERS, J.O., PELTON, L.S., RILEY, R.R., CROSS, H.R. and SMITH, G.C. 1989. Productivity of high quality beef with commercial Angus and high-percentage Wagyu steers. J. Anim. Sci. 67(Suppl. 1):164(Abstract).
  • ELIZONDO, E.B., SANDERS, J.O. and KNUTSON, R. 1989. Evaluation of five Zebu breeds for cow productivity. McGregor Field Day Report. TAES Tech. Rpt. 89-1:32-39.
  • ZIEHE, G.K., SANDERS, J.O. and RUCKER, M.D. 1989. Evaluation of udder characteristics of Fl females by sires of five Zebu breeds. McGregor Field Day Report. TAES Tech. RPT. 89-1:40-45.


Progress 01/01/88 to 12/30/88

Outputs
In 111 calvings out of F1 primiparous females, Angus-Hereford cross heifers experienced more dystocia (57.1%) than crosses of five different Bos indicus breeds with Hereford (4.3 to 21.0%); all calves were by Charolais bulls. Among the Bos indicus cross heifers, frequencies of dystocia were 4.3, 7.7, 10.0, 15.8, and 21.0%, for Nellore, Gir, Indu Brazil, Red Brahman and Gray Brahman crosses. Average postpartum weights for the Angus, Nellore, Gir, Indu Brazil, Red Brahman and Gray Brahman cross heifers were 370, 395, 390, 421, 424 and 421 kg. In 244 calvings (first to fourth parities and calves sired by Charolais and Salers bulls), average birth weights of calves out of Angus, Nellore, Gir, Indu Brazil, Red Brahman and Gray Brahman cross females were 37.2, 35.0, 33.0, 35.1, 35.5 and 36.4 kg, respectively. Average weaning weights of calves out of the above crosses were 219.4, 243.0, 240.9, 240.6, 252.4 and 249.4 kg. Charolais sired calves were 2.5 kg heavier at birth and 16.4 kg heavier at weaning than Salers crosses. All calves in the Charolais-Salers comparison were out of second parity and older cows; none of the second parity and older cows have experienced dystocia by either sire breed. In 91 steers and heifers out of cows of the Angus, Brahman, Hereford, Holstein and Jersey breeds and their crosses,those sired by modern Charolais bulls produced carcasses with slightly more marbling (S1 64 vs S1 51) and slightly less desirable yield grades (2.5 vs 2.3) than those sired by harolais bulls available prior to 1971.

Impacts
(N/A)

Publications

  • KERR, J.L., SANDERS, J.O. and PASCHAL, J.C. 1988. Comparisof of carcass characteristics of Angus, Gray Brahman, Gir, Indu Brazil, Nellore and REd Brahman sired calves. J. Anim. Sci. 66(Suppl. 1):230 (Abstract).
  • SANDERS, J.O. and ELIZONDO, E.B. 1988. Evaluation of five Zebu breeds for cow productivity. McGregor Field Day Report. TAES Tech. Rpt. 88-1:4-12.
  • ELIZONDO, E.B. AND SANDERS, J.O. 1988. A comparison of the Charolais and Salers as terminal sire breeds. McGregor Field Day Report. TAES Tech. Rpt. 88-1:1-3.
  • SANDERS, J.O., WILDE, B.L. AND BAKER, J.F. 1989. Evaluation of genetic change in the Charolais breed. Beef Cattle Research in Texas (in-press).
  • THALLMAN, R.M. 1988. Prediction of genetic values for weaning weight from field data on calves produced by embryo transfer. M.S. Thesis, Texas A&M Univ., College Station. 50p.
  • LUNT, D.K., SANDERS, J.O., RILEY, R.R. AND SMITH, G.C. 1988. Producing very high quality beef for export to Japan. McGregory Field Day Report. TAES Tech. Rpt. 88-1:190-193.
  • KERR, J.L. 1988. Evaluation of Zebu breeds based on postweaning growth, feedlot growth and carcass characteristics. M.S. Thesis, Texas A&M Univ., College Station. 90p.


Progress 01/01/87 to 12/30/87

Outputs
In 198 calvings out of mature cows of the Angus, Brahman, Hereford, Holstein andJersey breeds and their F1 crosses, calves by modern Charolais bulls had lighter birth weights (36.2 vs 38.8 kg) and shorter gestations (283.1 vs 286.0 d) than calves by Charolais bulls available prior to 1971. Preweaning gain did not differ significantly between the two sire groups, but calves by the older bulls had higher weaning weights (256.9 vs 249.2 kg). There was 7% dystocia and no significant difference between the two sire groups. Calves born in the spring had longer gestations (285.9 vs 283.1 d), more dystocia (9.1 vs 2.7%) and heavier birth weights (39.9 vs 35.1 kg) than those born in the fall. From 124 steers out of Hereford cows, those by Angus, Gray Brahman, Gir, Indu Brazil, Nellore and Red Brahman bulls had feedlot average daily gains from 13 to 17 mo of age of 1.56, 1.60, 1.47, 1.60, 1.50 and 1.57 kg. Final feedlot weights were 468, 500, 472, 480 and 511 kg. The Indu Brazil crosses had an average adjusted fat thickness of .99 cm vs values ranging from 1.15 to 1.3 for the other crosses. When adjusted for warm carcass weight, the Angus crosses had an average ribeye area of 78.4 cm vs values from 73.7 to 77.3 for the Zebu crosses. Average yield grades for the respective crosses were 2.5, 2.8, 2.7, 2.3, 2.7 and 2.7. The Angus crosses had higher average marbling score and quality grade (Sm 10 and Gd 91) than the Zebu crosses. The Nellore crosses had a slightly higher (P>.

Impacts
(N/A)

Publications

  • SANDERS, J.O. and PASCHAL, J.C. 1987. Postweaning growth and carcass characteristics of Senepol-, Angus- and Zebu-sired crossbred steers. International Senepol Research Symposium 1:123-128.
  • RANDEL, R.O., TOLLESON, D.R., NEUNDORFF, D.A., PASCHAL, J.C. and SANDERS, J.O. 1987. Performance of Senepol x Hereford and Angus x Hereford crossbred heifers from weaning through 30 days postpartum.
  • WILDE, B.L. 1987. Evaluation of genetic change in the Charolais breed for birth and growth characters. M. S. Thesis, Texas A&M Univ., College Station. 72p.
  • WILDE, B.L., SANDERS, J.O. and BAKER, J.F. 1987. Evaluation of progeny from Charolais sires available prior to 1971 and those available in 1984. J. Anim. Sci. 65(Suppl. 1):191 (Abstract).
  • PASCHAL, J.C., SANDERS, J.O. and KERR, J.L. 1987. Evaluation of five Zebu breeds for beef production. McGregor Field Day Report. TAES Tech. Rpt. 87-1:19-33.
  • SANDERS, J.O., PASCHAL, J.C. and THALLMAN, R.M. 1987. Pre-weaning performance of Senepol-, Angus-, and Zebu-sired calves in Texas. International Senepol Research Symposium 1:75-81.
  • BAKER, J.B. and SANDERS, J.O. 1987. Comparison of offsprin from Charolais sires available prior to 1971 and those available and those available in 1984.