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Full-Text Articles in Animal Sciences
Incidence Of Splayleg Pigs In Nebraska Litter Size Selection Lines, J. W. Holl, R. K. Johnson
Incidence Of Splayleg Pigs In Nebraska Litter Size Selection Lines, J. W. Holl, R. K. Johnson
Department of Animal Science: Faculty Publications
Genetic parameters for the splayleg (SL) condition were estimated from 37,673 records of pigs from six lines derived from a Large White–Landrace base population. Random selection for 22 generations was practiced in Lines C1 and C2. Line C2 was derived from C1 at Generation 8. Selection lines were as follows: 1) Line I, selected 11 generations for an index of ovulation rate and embryonic survival followed by 11 generations of selection for litter size; 2) Line IOL, derived from Line I at Generation 8 and which underwent eight generations of two-stage selection for ovulation rate and number of fully formed …
Unexpected Estimates Of Variance Components With A True Model Containing Genetic Competition Effects, L. Dale Van Vleck, J. P. Cassady
Unexpected Estimates Of Variance Components With A True Model Containing Genetic Competition Effects, L. Dale Van Vleck, J. P. Cassady
Department of Animal Science: Faculty Publications
Simulation of a model containing genetic competition effects was initiated to determine how well REML could untangle variances due to direct and competition genetic effects and pen effects. A two-generation data set was generated with six unrelated males that were each mated to five unrelated females to produce 300 progeny, from which 30 females (one per mating in previous generation) were mated to six unrelated males to produce 300 more progeny. Progeny were randomly assigned, six per pen, to 50 pens per generation. Parameters were Vg, Vc, Cgc, Vp, and Ve …
Estimates Of Genetic Parameters For Feed Intake, Feeding Behavior, And Daily Gain In Composite Ram Lambs, K. M. Cammack, Kreg A. Leymaster, T. G. Jenkins, Merlyn K. Nielsen
Estimates Of Genetic Parameters For Feed Intake, Feeding Behavior, And Daily Gain In Composite Ram Lambs, K. M. Cammack, Kreg A. Leymaster, T. G. Jenkins, Merlyn K. Nielsen
Department of Animal Science: Faculty Publications
Our objective was to estimate genetic parameters for feed intake, feeding behavior, and ADG in composite ram lambs (¹⁄₂ Columbia, ¹⁄₄ Hampshire, ¹⁄₄ Suffolk). Data were collected from 1986 to 1997 on 1,239 ram lambs from approximately 11 to 17 wk of age at the U.S. Meat Animal Research Center near Clay Center, NE. Feeding equipment consisted of an elevated pen with an entrance chute that permitted access to the feeder by only one ram lamb at a time, with disappearance of feed measured by an electronic weighing system. Ram lambs were grouped 11 per pen from 1986 to 1989, …
Unexpected Estimates Of Variance Components With A True Model Containing Genetic Competition Effects, L. D. Van Vleck, J. P. Morota
Unexpected Estimates Of Variance Components With A True Model Containing Genetic Competition Effects, L. D. Van Vleck, J. P. Morota
Department of Animal Science: Faculty Publications
Simulation of a model containing genetic competition effects was initiated to determine how well REML could untangle variances due to direct and competition genetic effects and pen effects. A two-generation data set was generated with six unrelated males that were each mated to five unrelated females to produce 300 progeny, from which 30 females (one per mating in previous generation) were mated to six unrelated males to produce 300 more progeny. Progeny were randomly assigned, six per pen, to 50 pens per generation. Parameters were Vg, Vc, Cgc, Vp, and Ve …
Covariance Functions And Random Regression Models For Cow Weight In Beef Cattle, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck
Covariance Functions And Random Regression Models For Cow Weight In Beef Cattle, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Data from the first four cycles of the Germplasm Evaluation program at the U.S. Meat Animal Research Center were used to evaluate weights of Angus, Hereford, and F1 cows produced by crosses of 22 sire and 2 dam (Angus and Hereford) breeds. Four weights per year were available for cows from 2 through 8 yr of age (AY) with age in months (AM). Weights (n &#;&#;61,798) were analyzed with REML using covariance function-random regression models (CF-RRM), with regression on orthogonal (Legendre) polynomials of AM. Models included fixed regression on AM and effects of cow line, age in years, season of …
Genetic Parameters For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score In Beef Cows, Jesus Arango, Larry V. Cundiff, L. Dale Van Vleck
Genetic Parameters For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score In Beef Cows, Jesus Arango, Larry V. Cundiff, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Weight (CW, n = 61,798), weight adjusted for condition score (WA), hip height (CH, n = 56,494), and condition score (CS, n = 61,434) of cows (2 through 8 yr of age) produced by crosses of 22 sire breeds with Angus and Hereford dams in the first four cycles of the Germplasm Evaluation (GPE) Program at the U.S. Meat Animal Research Center were used to estimate genetic parameters with REML. The model included sire breed, dam breed, age in years, season of measurement (1 to 4) and their interactions, and year of birth and pregnancy-lactation code (PL) as fixed effects …
Parameter Estimates For Direct And Maternal Genetic Effects On Yearling, Eighteen-Month, And Slaughter Weights Of Korean Native Cattle, J. W. Lee, S. B. Choi, Y. H. Jung, Jeffrey F. Keown, L. Dale Van Vleck
Parameter Estimates For Direct And Maternal Genetic Effects On Yearling, Eighteen-Month, And Slaughter Weights Of Korean Native Cattle, J. W. Lee, S. B. Choi, Y. H. Jung, Jeffrey F. Keown, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Data collected by the National Livestock Research Institute of the Rural Development Administration of Korea were used to estimate genetic parameters for yearling (YWT, n = 5,848), 18-mo (W18, n = 4,585), and slaughter (SWT, n = 2,279) weights for Korean Native cattle. Nine animal models were used to obtain REML estimates of genetic parameters: DP- 2 included genetic, uncorrelated dam, and residual random effects; DQ-2 included genetic, sire × region × year-season interaction, and residual random effects; DPQ- 2 was based on DQ-2 but included both interaction and dam effects; DMP-2 was based on DP-2 but with dam effect …
Comparison Of Models To Estimate Genetic Effects For Weaning Weight Of Angus Cattle, J. Dodenhoff, L. Dale Van Vleck, D. E. Wilson
Comparison Of Models To Estimate Genetic Effects For Weaning Weight Of Angus Cattle, J. Dodenhoff, L. Dale Van Vleck, D. E. Wilson
Department of Animal Science: Faculty Publications
Weaning weights from nine sets of Angus field data from three regions of the United States were analyzed. Six animal models were used to compare two approaches to account for an environmental dam-offspring covariance and to investigate the effects of sire × herd-year interaction on the genetic parameters. Model 1 included random direct and maternal genetic, maternal permanent environmental, and residual effects. Age at weaning was a covariate. Other fixed effects were age of dam and a herd-year-management-sex combination. Possible influence of a dam’s phenotype on her daughter’s maternal ability was modeled by including a regression on maternal phenotype (f …
Variance Components And Breeding Values For Growth Traits From Different Statistical Models, G. B. Ferreira, M. D. Macneil, L. Dale Van Vleck
Variance Components And Breeding Values For Growth Traits From Different Statistical Models, G. B. Ferreira, M. D. Macneil, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Estimates of genetic parameters resulting from various analytical models for birth weight (BWT, n = 4,155), 205-d weight (WWT, n = 3,884), and 365-d weight (YWT, n = 3,476) were compared. Data consisted of records for Line 1 Hereford cattle selected for postweaning growth from 1934 to 1989 at ARSUSDA, Miles City, MT. Twelve models were compared. Model 1 included fixed effects of year, sex, age of dam; covariates for birth day and inbreeding coefficients of animal and of dam; and random animal genetic and residual effects. Model 2 was the same as Model 1 but ignored inbreeding coefficients. Model …
Estimation Of Direct, Maternal, And Grandmaternal Genetic Effects For Weaning Weight In Several Breeds Of Beef Cattle, J. Dodenhoff, L. Dale Van Vleck, K. E. Gregory
Estimation Of Direct, Maternal, And Grandmaternal Genetic Effects For Weaning Weight In Several Breeds Of Beef Cattle, J. Dodenhoff, L. Dale Van Vleck, K. E. Gregory
Department of Animal Science: Faculty Publications
Weaning weights from nine parental breeds and three composites were analyzed to estimate variance due to grandmaternal genetic effects and to compare estimates for variance due to maternal genetic effects from two different models. Number of observations ranged from 794 to 3,465 per population. Number of animals in the pedigree file ranged from 1,244 to 4,326 per population. Two single-trait animal models were used to obtain estimates of covariance components by REML using an average information method. Model 1 included random direct and maternal genetic, permanent maternal environmental, and residual environmental effects as well as fixed sex ´ year and …
Genetic And Phenotypic Parameters For Carcass Traits Of American Shorthorn Beef Cattle, F. Pariacote, R. E. Hunsley, L. Dale Van Vleck
Genetic And Phenotypic Parameters For Carcass Traits Of American Shorthorn Beef Cattle, F. Pariacote, R. E. Hunsley, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Carcass measurements were taken on 1,292 steers and collected by the American Shorthorn Association. The sires were purebred or appendix-registered Shorthorn. Because all dams were not Shorthorn, genetic fractions of breeds of origin were determined for each dam. Measurements for hot carcass weight; dressing percentage; fat thickness; ribeye area; kidney, pelvic, and heart fat (KPH); marbling; and yield grade were analyzed jointly with a multivariate REML algorithm to estimate heritabilities of and genetic and phenotypic correlations among the traits. The sire model chosen as best fit of the data included fixed effects of herd of origin (377 classes), slaughter group …
Parameter Estimates For Direct, Maternal, And Grandmaternal Genetic Effects For Birth Weight And Weaning Weight In Hereford Cattle, J. Dodenhoff, L. Dale Van Vleck, Stephen D. Kachman, R. M. Koch
Parameter Estimates For Direct, Maternal, And Grandmaternal Genetic Effects For Birth Weight And Weaning Weight In Hereford Cattle, J. Dodenhoff, L. Dale Van Vleck, Stephen D. Kachman, R. M. Koch
Department of Animal Science: Faculty Publications
Birth and weaning weights adjusted for age of dam from four lines of Hereford cattle were analyzed to determine the relationships among grandmaternal, maternal, and direct genetic effects. Three lines were selected for 1) weaning weight (WWL), 2) yearling weight (YWL), and 3) an index of yearling weight and muscle score (IXL). The fourth line was an unselected control line (CTL). Numbers of observations ranged from 1,699 (CTL) to 2,811 (WWL), and number of animals in the pedigree file ranged from 2,266 to 3,192. Two animal models were used to obtain estimates by REML using an average information method. Model …
Influence Of Dominance Relationships On The Estimation Of Dominance Variance With Sire-Dam Subclass Effects, N. Gengler, L. Dale Van Vleck, M. D. Macneil, I. Misztal, F. A. Pariacote
Influence Of Dominance Relationships On The Estimation Of Dominance Variance With Sire-Dam Subclass Effects, N. Gengler, L. Dale Van Vleck, M. D. Macneil, I. Misztal, F. A. Pariacote
Department of Animal Science: Faculty Publications
Two data sets from the USDA Livestock and Range Research Laboratory were analyzed to study dominance variance and the influence of dominance relationships. The first consisted of 4,155 birth weight (3,884 weaning weight) records of inbred USDA Line 1 Herefords. The second consisted of 8,065 birth weight (7,380 weaning weight) records from a line-cross experiment with five lines. Two models were used. Both included fixed effects of year-sex of calf and age of dam, and covariates for calving date, inbreeding of animal, and inbreeding of dam. For the second set, additional covariates were line composition and heterozygosity coefficients. Random effects …
Estimation Of Variances Due To Direct And Maternal Effects For Growth Traits Of Nelore Cattle, J. P. Eler, L. Dale Van Vleck, J. B. S. Ferraz, R. B. Lobo
Estimation Of Variances Due To Direct And Maternal Effects For Growth Traits Of Nelore Cattle, J. P. Eler, L. Dale Van Vleck, J. B. S. Ferraz, R. B. Lobo
Department of Animal Science: Faculty Publications
Estimates of (co)variance components and genetic parameters were obtained for birth, 205-d, and 365-d weight for Nelore cattle in Brazil, using single and multiple-trait animal models. Data were from the Brazilian Zebu Breeders Association (ABCZ). Records of 27,549 calves sired by 587 bulls and raised on pasture in 57 herds were analyzed by restricted maximum likelihood fitting an animal model including direct and maternal genetic and permanent environmental effects. Single and multiple- trait analyses were carried out. Heritability estimates for direct effects were lower than previous values reported for the Nelore breed. The estimates for maternal genetic effects showed that …
Estimation Of Variances Due To Direct And Maternal Effects For Growth Traits Of Nelore Cattle, J. P. Eler, L. Dale Van Vleck, J. B. S. Ferraz, R. B. Lobo
Estimation Of Variances Due To Direct And Maternal Effects For Growth Traits Of Nelore Cattle, J. P. Eler, L. Dale Van Vleck, J. B. S. Ferraz, R. B. Lobo
Department of Animal Science: Faculty Publications
Estimates of (co)variance components and genetic parameters were obtained for birth, 205-d, and 365-d weight for Nelore cattle in Brazil, using single and multiple-trait animal models. Data were from the Brazilian Zebu Breeders Association (ABCZ). Records of 27,549 calves sired by 587 bulls and raised on pasture in 57 herds were analyzed by restricted maximum likelihood fitting an animal model including direct and maternal genetic and permanent environmental effects. Single and multiple- trait analyses were carried out. Heritability estimates for direct effects were lower than previous values reported for the Nelore breed. The estimates for maternal genetic effects showed that …
Animal Model Estimation Of Genetic Parameters And Response To Selection For Litter Size And Weight, Growth, And Backfat In Closed Seedstock Populations Of Large White And Landrace Swine, Jose Bento S. Ferraz, Rodger K. Johnson
Animal Model Estimation Of Genetic Parameters And Response To Selection For Litter Size And Weight, Growth, And Backfat In Closed Seedstock Populations Of Large White And Landrace Swine, Jose Bento S. Ferraz, Rodger K. Johnson
Department of Animal Science: Faculty Publications
Records from 2,495 litters and 14,605 Landrace and Large White pigs from two farms, but established from the same base population and run as replicated selection lines, were analyzed. Selection within herd was on estimated breeding values weighted by economic values. Animal models and REML procedures were used to estimate genetic, phenotypic, and environmental parameters for the number of pigs born alive (NBA), litter weight at 21 d (LW), average daily gain from approximately 30 to 104 kg (AD GI, and backfat thickness adjusted to 104 kg (BF). Random animal genetic effects ( 01, permanent (NBA and LW) or litter …
Estimates Of Genetic Parameters For Direct And Maternal Effects On Embryonic Survival In Swine, Luis T. Gama, Keith G. Boldman, Rodger K. Johnson
Estimates Of Genetic Parameters For Direct And Maternal Effects On Embryonic Survival In Swine, Luis T. Gama, Keith G. Boldman, Rodger K. Johnson
Department of Animal Science: Faculty Publications
Survival of 16,838 potential embryos was determined by counting corpora lutea and fetuses at 50 d of gestation for 1,081 litters by 225 sires. These data, coded as 1 or 0 depending on whether an ovulation was represented by a fetus, were used to estimate direct and maternal additive genetic variances and their covariance for embryonic survival. Data were from fist-parity gilts of a Large White-Landrace composite population subdivided into two lines, one selected for an index of ovulation rate and embryonic survival for seven generations and a contemporary control line. Variance components were obtained by ANOVA and expectations of …