Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Life Sciences
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 …
Comparison Of Methods Of Estimating Variance Components In Pigs, J. W. Keele, T. E. Long, R. K. Johnson
Comparison Of Methods Of Estimating Variance Components In Pigs, J. W. Keele, T. E. Long, R. K. Johnson
Department of Animal Science: Faculty Publications
Components of variance due to average effects of genes (σ g2), environmental effects common to littermates (σ c2), and environmental effects peculiar to individual pigs (σ e2 )were estimated (ˆ) by the Pseudo Expectation Approach (PE). Data were litter size (LS), backfat (BF; centimeter) and ADG (kilograms/day) collected from the Nebraska Gene Pool swine population between 1967 and 1986. Mean square errors (MSE) for ĥ2 and ĉ2 (ôg2 and ôc2 divided by phenotypic variance) by PE and nested ANOVA and h2 estimated by offspring on parent regression (REGOP) …
Heritability Estimates Of Transformations Of Normally Distributed Records, A. L. Destefano, L. Dale Van Vleck
Heritability Estimates Of Transformations Of Normally Distributed Records, A. L. Destefano, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Milk yields were simulated for identical twin and parent-progeny pairs to determine effect of transformations on genetic variance. Use of identical twin pairs excludes variability due to Mendelian sampling and contribution by the other parent present in parent-progeny records. Phenotypic variances of 616,800; 1,439,200, and 2,261,600 and means from 2267 to 13,603 by increments of 2267 were used for linear scale records. Phenotypic variances of .0100O, .01875, and .02750 and means equal to the natural logarithm of the means for linear scale were used for log scale records. Heritability varied from .05 to .95 by increments of .lo. For each …