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Full-Text Articles in Life Sciences
Estimation Of Breed-Specific Heterosis Effects For Birth, Weaning, And Yearling Weight In Cattle, Lauren N. Schiermiester, R. M. Thallman, Larry Kuehn, Stephen D. Kachman, Matthew L. Spangler
Estimation Of Breed-Specific Heterosis Effects For Birth, Weaning, And Yearling Weight In Cattle, Lauren N. Schiermiester, R. M. Thallman, Larry Kuehn, Stephen D. Kachman, Matthew L. Spangler
Department of Animal Science: Faculty Publications
Heterosis, assumed proportional to expected breed heterozygosity, was calculated for 6834 individuals with birth, weaning and yearling weight records from Cycle VII and advanced generations of the U.S. Meat Animal Research Center (USMARC) Germplasm Evaluation (GPE) project. Breeds represented in these data included: Angus, Hereford, Red Angus, Charolais, Gelbvieh, Simmental, Limousin and Composite MARC III. Heterosis was further estimated by proportions of British × British (B × B), British × Continental (B × C) and Continental × Continental (C × C) crosses and by breed-specific combinations. Model 1 fitted fixed covariates for heterosis within biological types while Model 2 fitted …
Genome-Wide Prediction Of Age At Puberty And Reproductive Longevity In Sows, Julie Kathleen Tart, Rodger K. Johnson, Justin W. Bundy, N. N. Ferdinand, A. M. Mcknite, Jennifer R. Wood, Phillip S. Miller, M. F. Rothschild, Matthew L. Spangler, Dorian J. Garrick, Stephen D. Kachman, Daniel C. Ciobanu
Genome-Wide Prediction Of Age At Puberty And Reproductive Longevity In Sows, Julie Kathleen Tart, Rodger K. Johnson, Justin W. Bundy, N. N. Ferdinand, A. M. Mcknite, Jennifer R. Wood, Phillip S. Miller, M. F. Rothschild, Matthew L. Spangler, Dorian J. Garrick, Stephen D. Kachman, Daniel C. Ciobanu
Department of Animal Science: Faculty Publications
Traditional selection for sow reproductive longevity is ineffective due to low heritability and late expression of the trait. Incorporation of DNA markers into selection programs is potentially a more practical approach for improving sow lifetime productivity. Using a resource population of crossbred gilts, we explored pleiotropic sources of variation that influence age at puberty and reproductive longevity. Of the traits recorded before breeding, only age at puberty significantly affected the probability that females would produce a first parity litter. The genetic variance explained by 1-Mb windows of the sow genome, compared across traits, uncovered regions that influence both age at …
Effects Of Genetic Type And Protein Levels On Growth Of Swine, O.W. Robison, L. L. Christian, R. Goodwin, R. K. Johnson, J. W. Mabry, R. K. Miller, M. D. Tokach
Effects Of Genetic Type And Protein Levels On Growth Of Swine, O.W. Robison, L. L. Christian, R. Goodwin, R. K. Johnson, J. W. Mabry, R. K. Miller, M. D. Tokach
Department of Animal Science: Faculty Publications
A total of 1,588 pigs representing six genetic lines were included in this study. These lines were selected to represent a wide range of biological types for appetite, rate and composition of gain, and meat quality traits. Each line was fed four different diets differing in lysine content. Barrows and gilts were used in the experiment, and pigs were randomly assigned to come off test at one of three weights (113.6, 131.8, or 150 kg). Rates of increase in weight, backfat thickness, and longissimus muscle area were essentially linear. Genetic type and diet influenced (P < .05) rates of change in weight, backfat thickness, and longissimus muscle area and 10th rib fat depth, carcass longissimus muscle area, and dressing percentage. Genetic type × diet interactions were significant for weight change and 10th rib fat. As off-test-weight class increased fat and longissimus muscle area increased in linear fashion. In general, interactions associated with diet resulted from feeding the diet lowest in lysine. There was little evidence of genetic type × diet interactions. If those interactions that tested significant are real, they are a result of extremes in both genetic type (high fatness) and lysine level (low). Slaughtering pigs at heavier weights results in no change in rate of gain over the feeding period and linear increases in longissimus muscle area and backfat thickness.
Genetic Correlations For Daily Gain Between Ram And Ewe Lambs Fed In Feedlot Conditions And Ram Lambs Fed In Pinpointer Units, L. Dale Van Vleck, Kreg A. Leymaster, Thomas G. Jenkins
Genetic Correlations For Daily Gain Between Ram And Ewe Lambs Fed In Feedlot Conditions And Ram Lambs Fed In Pinpointer Units, L. Dale Van Vleck, Kreg A. Leymaster, Thomas G. Jenkins
Department of Animal Science: Faculty Publications
When performance is recorded in automated facilities that measure feed intake of individual lambs that are penned in a group, such as Pinpointer units, a legitimate question is the degree to which daily gain is genetically correlated with daily gain achieved under feedlot conditions. Lambs were from a composite population (½Columbia, ¼ Suffolk, and ¼ Hampshire germplasm) and of the F2 or more advanced generations. Data were daily gains of 1,101 rams (PR) fed in Pinpointer units (11 to 17 wk of age) and 2,021 rams (FR) and 3,513 ewes (FE) fed under feedlot conditions (9- or 10-wk period …
Implications Of Cloning For Breed Improvement Strategies: Are Traditional Methods Of Animal Improvement Obsolete?, L. Dale Van Vleck
Implications Of Cloning For Breed Improvement Strategies: Are Traditional Methods Of Animal Improvement Obsolete?, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Can the optimum animal be defined? Will that definition change over time, by location, by market demand? First, assume what may be impossible, that the perfect animal can be defined or that only a limited number of definitions of “perfect” are needed. Then, can the “perfect” animal to match a definition be found? Suppose such an animal is found. Then the question to be answered before trying to clone as a method of genetic improvement becomes “Is the animal perfect because of phenotype or genotype?” In other words, the P = G + E problem exists, which requires traditional methods …
Genotypic Expression At Different Ages: Ii. Wool Traits Of Sheep, H. Okut, C. M. Bromley, L. Dale Van Vleck, G. D. Snowder
Genotypic Expression At Different Ages: Ii. Wool Traits Of Sheep, H. Okut, C. M. Bromley, L. Dale Van Vleck, G. D. Snowder
Department of Animal Science: Faculty Publications
Genetic parameters for wool traits for Columbia, Polypay, Rambouillet, and Targhee breeds of sheep were estimated with single- and multiple-trait analyses using REML with animal models. Traits considered were fleece grade, fleece weight, and staple length. Total number of observations ranged from 11,673 to 34,746 for fleece grade and fleece weight and from 3,500 to 11,641 for staple length for the four breeds. For single-trait analyses, data were divided by age of ewe: young ages (age of 1 yr), middle ages (ages of 2 and 3 yr), and older ages (age greater than 3 yr). Heritability estimates averaged over breeds …
Genotypic Expression At Different Ages: I. Prolificacy Traits Of Sheep, H. Okut, C. M. Bromley, L. Dale Van Vleck, G. D. Snowder
Genotypic Expression At Different Ages: I. Prolificacy Traits Of Sheep, H. Okut, C. M. Bromley, L. Dale Van Vleck, G. D. Snowder
Department of Animal Science: Faculty Publications
Genetic parameters for prolificacy traits for Columbia (COLU), Polypay (POLY), Rambouillet (RAMB), and Targhee (TARG) breeds of sheep were estimated with REML using animal models. Traits were number of live births (LAB), litter size at birth (LSB) and weaning (LSW), and litter weight weaned (LWW). Numbers of observations ranged from 5,140 to 7,095 for prolificacy traits and from 5,101 to 8,973 for litter weight weaned for the four breeds. For single-trait analyses, ewes were classified as young (1 yr old), middle-aged (2 and 3 yr old), or older (> 3 yr old). After single-trait analyses, three-trait analyses were done for …
Multiple-Trait Gibbs Sampler For Animal Models: Flexible Programs For Bayesian And Likelihood-Based (Co)Variance Component Inference, C. P. Van Tassell, L. Dale Van Vleck
Multiple-Trait Gibbs Sampler For Animal Models: Flexible Programs For Bayesian And Likelihood-Based (Co)Variance Component Inference, C. P. Van Tassell, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
A set of FORTRAN programs to implement a multiple-trait Gibbs sampling algorithm for (co)variance component inference in animal models (MTGSAM) was developed. The MTGSAM programs are available to the public. The programs support models with correlated genetic effects and arbitrary numbers of covariates, fixed effects, and independent random effects for each trait. Any combination of missing traits is allowed. The programs were used to estimate variance components for 50 replicates of simulated data. Each replicate consisted of 50 animals of each sex in each of four generations, for 400 animals in each replicate for two traits. For MTGSAM, informative prior …
Variances Of Additive And Dominance Genetic Effects For Ovulation And Twinning Rates In A Population Selected For Twinning, L. Dale Van Vleck, K. E. Gregory
Variances Of Additive And Dominance Genetic Effects For Ovulation And Twinning Rates In A Population Selected For Twinning, L. Dale Van Vleck, K. E. Gregory
Department of Animal Science: Faculty Publications
Estimates of variances due to additive and dominance genetic effects and permanent and temporary environmental effects were obtained for ovulation and twinning rates from a composite population selected for twinning rate. Measures of ovulation rate after 11 mo of age on 2,317 heifers with a total of 19,209 measures were used. Twinning measures were on 1,522 first-parity cows, 1,311 later-parity cows with a total of 3,571 measures, and 1,704 all-parity cows with 5,100 measures. Models included fixed effects of year-season-age at calving for twinning, and year-season of birth, age in months, and calendar month of measurement for ovulation rate. Four …