The Experts below are selected from a list of 2334 Experts worldwide ranked by ideXlab platform

L. L. Benyshek - One of the best experts on this subject based on the ideXlab platform.

  • genetic parameter estimates for carcass and yearling ultrasound measurements in Brangus cattle
    Journal of Animal Science, 1998
    Co-Authors: D W Moser, L A Kriese, J K Bertrand, Ignacy Misztal, L. L. Benyshek
    Abstract:

    : Carcass measurements of 12th-rib fat thickness (CARCFAT), longissimus muscle area (CARCLMA), and weight (CARCWT) on 2,028 Brangus and Brangus-sired fed steers and heifers, as well as yearling weights (YWT) and ultrasound measures of 12th-rib fat thickness (USFAT) and longissimus muscle area (USLMA) on 3,583 Brangus bulls and heifers were analyzed to estimate genetic parameters. Data were analyzed using a six-trait animal model and an average information REML algorithm. The model included fixed effects for contemporary group and breed of dam, covariates for age at slaughter or measurement, and random animal and residual effects. Heritabilities for CARCFAT, CARCLMA, CARCWT, USFAT, USLMA, and YWT were .27+/-.05, .39+/-.05, .59+/-.06, .11+/-.03, .29+/-.04, and .40+/-.04, respectively. Genetic correlations between CARCFAT and USFAT, CARCLMA and USLMA, and CARCWT and YWT were .69+/-.18, .66+/-.14, and .61+/-.11, respectively. The favorable and moderately strong genetic correlations between carcass measurements and similar yearling breeding-animal ultrasound measurements indicate that such measurements of 12th-rib fat and longissimus muscle area are useful in predicting genetic values for carcass leanness and longissimus muscle area. Selection using yearling ultrasound measurements of breeding cattle should result in predictable genetic improvement for carcass characteristics. Inclusion of yearling ultrasound measurements for fat thickness and longissimus muscle area should enhance national cattle evaluation programs.

  • Age adjustment factors, heritabilities and genetic correlations for scrotal circumference and related growth traits in Hereford and Brangus bulls.
    Journal of animal science, 1991
    Co-Authors: L A Kriese, J K Bertrand, L. L. Benyshek
    Abstract:

    Field data records on 10,511 Hereford and 2,522 Brangus bulls between 330 and 430 d of age were analyzed to find age of calf and age of dam adjustment factors for yearling scrotal circumference. Age of calf adjustment factors were .024 cm/d for Hereford bulls and .041 cm/d for Brangus bulls. Sons of Hereford dams were adjusted to a 6- to 8-yr dam age basis by adding .7, .3, .2, .2 or .3 cm for dams 2, 3, 4, 5 or 8 or more years old, respectively. Age of dam adjustment factors for Brangus bulls were .8, .4, .3 and .2 for dams 2, 3, 4 or 8 or more years old, respectively. Variance and covariance components for yearling scrotal circumference and several growth traits were estimated within breed using multiple-trait models and pseudo expectations involving the solutions and the right-hand sides of the mixed-model equations. Additive heritability estimates for yearling scrotal circumference of .53 and .16 were found for Hereford and Brangus bulls, respectively. Maternal heritability estimates of .12 and .10 were found for Hereford and Brangus bulls, respectively. Genetic correlations between yearling scrotal circumference and other growth traits were positive for both sets of data indicating that selection for yearling scrotal circumference should not adversely affect other growth traits in either breed. Environmental correlation estimates between yearling scrotal circumference and adjusted birth weight and between yearling scrotal circumference and adjusted 205-d weight and adjusted 365-d height were positive and moderate in magnitude for both breeds.

Casper Nyamukanza - One of the best experts on this subject based on the ideXlab platform.

  • Growth performance of Brangus steers fed graded levels of sun-dried broiler litter as a substitute for cottonseed cake
    Tropical Animal Health and Production, 2015
    Co-Authors: Lawrence Masaka, Victor Mhaka, Marvelous Sungirai, Casper Nyamukanza
    Abstract:

    An experiment was conducted to determine the optimum inclusion levels of dried broiler litter (DBL) as a substitute for cottonseed cake (CSC) in fattening diets for Brangus steers. Thirty Brangus steers were randomly allocated to five groups of six animals each. Each group was fed one of the experimental diets which had CSC substituted for DBL at levels of 0 (DBL0), 50 (DBL50), 100 (DBL100), 150 (DBL150) and 200 g/kg (DBL200). Average daily gain (ADG), dry matter intake and live weight gain (LWG) were measured over a period of 90 days, and the results were analysed using the MIXED procedures of SAS. Linear and quadratic effects of DBL inclusion on dry matter intake, LWG and ADG were also determined. Results showed interactions between diet and time that significantly affected ADG and LWG ( p  

  • growth performance of Brangus steers fed graded levels of sun dried broiler litter as a substitute for cottonseed cake
    Tropical Animal Health and Production, 2015
    Co-Authors: Lawrence Masaka, Victor Mhaka, Marvelous Sungirai, Casper Nyamukanza
    Abstract:

    An experiment was conducted to determine the optimum inclusion levels of dried broiler litter (DBL) as a substitute for cottonseed cake (CSC) in fattening diets for Brangus steers. Thirty Brangus steers were randomly allocated to five groups of six animals each. Each group was fed one of the experimental diets which had CSC substituted for DBL at levels of 0 (DBL0), 50 (DBL50), 100 (DBL100), 150 (DBL150) and 200 g/kg (DBL200). Average daily gain (ADG), dry matter intake and live weight gain (LWG) were measured over a period of 90 days, and the results were analysed using the MIXED procedures of SAS. Linear and quadratic effects of DBL inclusion on dry matter intake, LWG and ADG were also determined. Results showed interactions between diet and time that significantly affected ADG and LWG (p < 0.05). Both ADG and LWG decreased with increases in DBL inclusion with the depressed performance becoming more pronounced with time. Linear and non-linear decreases in LWG and ADG, respectively, were observed with increasing levels of DBL. The DBL50 diet resulted in performance that was similar to DBL50 and was 4 % cheaper. Broiler litter can be used as a supplement for conventional protein sources, but at higher inclusion levels, it needs to be augmented by increased fermentable energy.

D W Moser - One of the best experts on this subject based on the ideXlab platform.

  • genetic parameter estimates for carcass and yearling ultrasound measurements in Brangus cattle
    Journal of Animal Science, 1998
    Co-Authors: D W Moser, L A Kriese, J K Bertrand, Ignacy Misztal, L. L. Benyshek
    Abstract:

    : Carcass measurements of 12th-rib fat thickness (CARCFAT), longissimus muscle area (CARCLMA), and weight (CARCWT) on 2,028 Brangus and Brangus-sired fed steers and heifers, as well as yearling weights (YWT) and ultrasound measures of 12th-rib fat thickness (USFAT) and longissimus muscle area (USLMA) on 3,583 Brangus bulls and heifers were analyzed to estimate genetic parameters. Data were analyzed using a six-trait animal model and an average information REML algorithm. The model included fixed effects for contemporary group and breed of dam, covariates for age at slaughter or measurement, and random animal and residual effects. Heritabilities for CARCFAT, CARCLMA, CARCWT, USFAT, USLMA, and YWT were .27+/-.05, .39+/-.05, .59+/-.06, .11+/-.03, .29+/-.04, and .40+/-.04, respectively. Genetic correlations between CARCFAT and USFAT, CARCLMA and USLMA, and CARCWT and YWT were .69+/-.18, .66+/-.14, and .61+/-.11, respectively. The favorable and moderately strong genetic correlations between carcass measurements and similar yearling breeding-animal ultrasound measurements indicate that such measurements of 12th-rib fat and longissimus muscle area are useful in predicting genetic values for carcass leanness and longissimus muscle area. Selection using yearling ultrasound measurements of breeding cattle should result in predictable genetic improvement for carcass characteristics. Inclusion of yearling ultrasound measurements for fat thickness and longissimus muscle area should enhance national cattle evaluation programs.

Milt Thomas - One of the best experts on this subject based on the ideXlab platform.

  • Genomic Breed Composition of Selection Signatures in Brangus Beef Cattle.
    Frontiers in genetics, 2020
    Co-Authors: Tiago Do Prado Paim, Milt Thomas, El Hamidi A. Hay, C. Wilson, Larry A. Kuehn, Samuel Rezende Paiva, Concepta Mcmanus, H. D. Blackburn
    Abstract:

    Cattle breeding routinely uses crossbreeding between subspecies (Bos taurus taurus and Bos taurus indicus) to form composite breeds, such as Brangus. These composite breeds provide an opportunity to identify recent selection signatures formed in the new population and evaluate the genomic composition of these regions of the genome. Using high-density genotyping, we first identified runs of homozygosity (ROH) and calculated genomic inbreeding. Then, we evaluated the genomic composition of the regions identified as selected (selective sweeps) using a chromosome painting approach. The genomic inbreeding increased at approximately 1% per generation after composite breed formation, showing the need of inbreeding control even in composite breeds. Three selected regions in Brangus were also identified as Angus selection signatures. Two regions (chromosomes 14 and 21) were identified as signatures of selection in Brangus and both founder breeds. Five of the 10 homozygous regions in Brangus were predominantly Angus in origin (probability >80%), and the other five regions had a mixed origin but always with Brahman contributing less than 50%. Therefore, genetic events, such as drift, selection, and complementarity, are likely shaping the genetic composition of founder breeds in specific genomic regions. Such findings highlight a variety of opportunities to better control the selection process and explore heterosis and complementarity at the genomic level in composite breeds.

  • Bayesian genome-wide association analysis of growth and yearling ultrasound measures of carcass traits in Brangus heifers
    Journal of animal science, 2012
    Co-Authors: Sunday O. Peters, Dorian J. Garrick, G.a. Silver, Kadir Kizilkaya, Rohan L. Fernando, James M. Reecy, R. L. Weaber, Milt Thomas
    Abstract:

    Data from developing Brangus heifers (3/8 Brahman-Bos indicus × 5/8 Angus-Bos taurus; n ≈ 802 from 67 sires) registered with International Brangus Breeders Association were analyzed to detect QTL associated with growth traits and ultrasound measures of carcass traits. Genotypes were from BovineSNP50 (Infinium BeadChip, Illumina, San Diego, CA; 53,692 SNP). Phenotypes included BW collected at birth and ∼205 and 365 d of age, and yearling ultrasound assessment of LM area, percent intramuscular fat, and depth of rib fat. Simultaneous association of SNP windows with phenotype were undertaken with Bayes C analyses, using GenSel software. The SNP windows were ≈ 5 SNP in length. Analyses fitted a mixture model that treated SNP effects as random, with an assumed fraction pi = 0.999 having no effect on phenotype. Bootstrap analyses were used to obtain significance values for the SNP windows with the greatest contribution to observed variation. The SNP windows with P < 0.01 were considered as QTL associated with a trait in which case their location was queried from dbSNP and the presence of a previously reported QTL in that location was checked in CattleQTLdb. For 9 traits, QTL were mapped to 139 regions on 25 chromosomes. Forty-one of these QTL were already described in CattleQTLdb, so 98 are new additions. The SNP windows on chromosomes 1, 3, and 6 were associated with multiple traits (i.e., 205- and 365- d BW, and ADG from birth to 205 and 365 d of age). Several chromosomes harbored regions associated with multiple traits; however, the SNP that comprised the window often varied among traits (i.e., chromosomes 1, 3, 4, 5, 6, 7, 9, 10, 11, 13, 14, 15, 16, 20, 21, 22, 24, 28, and 29). Results from whole genome association of SNP with growth and ultrasound carcass traits in developing Brangus heifers confirmed several published QTL and detected several new QTL.

  • Grazing Distribution and Diet Quality of Angus, Brangus, and Brahman Cows in the Chihuahuan Desert
    Rangeland Ecology & Management, 2012
    Co-Authors: Morgan L. Russell, Milt Thomas, Derek W. Bailey, Barbara K. Witmore
    Abstract:

    Abstract Grazing distribution can be improved by using adapted cattle breeds that travel to distant areas of extensive pastures. A 2-yr study was conducted to evaluate grazing distribution and diet quality of Angus, Brangus, and Brahman cows (seven cows per breed group) in the Chihuahuan Desert during three seasons (winter, early summer, and late summer) using three pastures. Two GPS collars were randomly assigned to each breed group and cow positions were logged every 10 min for 10- to 14-d periods in each pasture (3 periods · season -1 ). In 2008, breed groups were evaluated in separate pastures and data were analyzed as a 3 × 3 Latin square design. In 2009, all breed groups were evaluated at the same time in the same pastures. Fecal samples were collected in 2008 and analyzed using near infrared spectroscopy (NIRS) to estimate diet quality. If positions recorded when cows were resting were excluded, Brahman cows traveled greater distances per day than Angus cows throughout the study and greater ( P  ≤ 0.10) than Brangus cows in all but one season during 2009. No differences in average distance to water were detected ( P  s 0.10) among breed groups. During early summer in 2008 and early and late summer in 2009, Angus cows maintained a more linear grazing path ( P  ≤ 0.10) than Brangus or Brahman cows. Brahman cows displayed more sinuous grazing paths ( P  ≤ 0.10) than other breeds during early and late summer seasons in 2009. In 2008, no differences in crude protein content of diets were detected ( P  s 0.10) among breed groups during all seasons. Spatial movement patterns of Brahman cows appeared to differ from Angus and Brangus cows; however, there was no evidence to suggest that there was any advantage in use of areas far from water by any breed group.

  • Metabolic Hormone Profiles and Evaluation of Associations of Metabolic Hormones with Body Fat and Reproductive Characteristics of Angus, Brangus, and Brahman Heifers1
    The Professional Animal Scientist, 2006
    Co-Authors: R. Lopez, Milt Thomas, Dennis M. Hallford, Duane H. Keisler, Belal S. Obeidat, G.a. Silver, M. D. Garcia, C. R. Krehbiel
    Abstract:

    Metabolic hormone profiles and their associations with measures of body fat and reproduction were evaluated among Angus, Brangus, and Brahman heifers (n = 8/breed). Heifers of similar age from breeding programs in semi-arid environments were pen-fed for 10 wk prior to

  • Relationships of metabolic hormones and serum glucose to growth and reproductive development in performance-tested Angus, Brangus, and Brahman bulls.
    Journal of animal science, 2002
    Co-Authors: Milt Thomas, R. M. Enns, Dennis M. Hallford, Duane H. Keisler, Belal S. Obeidat, C D Morrison, J. A. Hernandez, W. D. Bryant, R. Flores, R. Lopez
    Abstract:

    Understanding mechanisms that regu- late growth and reproduction are important for improv- ing selection strategies in cattle. In this study, Angus, Brangus, and Brahman bulls (n = 7 per breed) of similar age were selected from a group of 65 weanlings. Bulls were evaluated after weaning (i.e., ∼ 6 mo of age) for 112 d for serum concentrations of metabolic hormones and glucose, growth, and reproductive traits. Perfor- mance data and blood sera were collected on d 0, 28, 56, 84, and 112. Sera were also collected in periods from d 50 to 59 (56D) and 103 to 112 (112D). Angus bulls were heavier (P < 0.05) throughout the study than Brahman bulls and were heavier than Brangus bulls on d 56, 84, and 112. Initial and final BW for Angus, Brangus, and Brahman bulls were 292.7, 260.6, and 230.4 and 468.3, 435.6, and 350.7 ± 12 kg, respectively. Conversely, Brahman bulls had greater hip height (P < 0.05) than Brangus, and Brangus were taller (P < 0.05) than An- gus. Angus bulls had the greatest (P < 0.05) scrotal circumference (SC) and Brahman bulls the least. Mean SC across days was 31.5, 29.7, and 25.0 ± 0.6 cm for the three respective breeds. Serum testosterone was greater (P < 0.01) in Angus and Brangus bulls (10.0

Renata S. T. Silva - One of the best experts on this subject based on the ideXlab platform.

  • Performance, digestibility, microbial protein synthesis, and body composition of Brangus x Zebu steers on tropical pasture receiving supplementation
    Tropical Animal Health and Production, 2020
    Co-Authors: Felipe R. A. F. Valle, Carlos A. A. Fontes, Alberto M. Fernandes, Tadeu S. Oliveira, Elizabeth F. Processi, Renata S. T. Silva
    Abstract:

    The use of additional supplement can affect ruminant performance by increasing the animal weight gain and maximizing profits from the activity. Thus, the objective of this study was to evaluate the influence of protein-energy supplementation on microbial synthesis, animal performance, nutrient digestibility, and body composition of Brangus x Zebu steers on pasture. The experiment lasted 160 days and included 36 animals divided into two groups; 18 steers received protein-energy supplementation (PES), and the other 18 received non-supplementation (NPES). Individual pasture intake and nutrient digestibility were estimated using the double indicator technique—chromium oxide and lignin in potassium permanganate. Spot urine samples were collected from 36 animals to determine creatinine, allantoin, and uric acid concentrations. All animals were slaughtered at the end of the experiment to evaluate body composition. There was increase in intake ( P   0.05) for body composition between treatments. Therefore, the use of protein-energy supplementation for steers on pasture allowed higher microbial protein synthesis and better utilization of nutrients, which resulted in better animal performance. The use of protein-energy supplementation at 0.6% BW did not alter the carcass composition of Brangus x Zebu steers. However, it recommends protein-energy supplementation in pasture systems during the rainy period or using an irrigation system.

  • Performance, digestibility, microbial protein synthesis, and body composition of Brangus x Zebu steers on tropical pasture receiving supplementation.
    Tropical animal health and production, 2020
    Co-Authors: Felipe R. A. F. Valle, Alberto M. Fernandes, Tadeu S. Oliveira, Elizabeth F. Processi, Carlos Augusto De Alencar Fontes, Renata S. T. Silva
    Abstract:

    The use of additional supplement can affect ruminant performance by increasing the animal weight gain and maximizing profits from the activity. Thus, the objective of this study was to evaluate the influence of protein-energy supplementation on microbial synthesis, animal performance, nutrient digestibility, and body composition of Brangus x Zebu steers on pasture. The experiment lasted 160 days and included 36 animals divided into two groups; 18 steers received protein-energy supplementation (PES), and the other 18 received non-supplementation (NPES). Individual pasture intake and nutrient digestibility were estimated using the double indicator technique-chromium oxide and lignin in potassium permanganate. Spot urine samples were collected from 36 animals to determine creatinine, allantoin, and uric acid concentrations. All animals were slaughtered at the end of the experiment to evaluate body composition. There was increase in intake (P   0.05) in pasture nutrient intake between treatments. Supplementation increased microbial nitrogen (P   0.05) between the models, so it was adopted a common equation for both treatments. There was no difference (P > 0.05) for body composition between treatments. Therefore, the use of protein-energy supplementation for steers on pasture allowed higher microbial protein synthesis and better utilization of nutrients, which resulted in better animal performance. The use of protein-energy supplementation at 0.6% BW did not alter the carcass composition of Brangus x Zebu steers. However, it recommends protein-energy supplementation in pasture systems during the rainy period or using an irrigation system.