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Full-Text Articles in Animal Sciences
Comparison Of Methods Of Predicting Breeding Values Of Swine, J. W. Keele, R. K. Johnson, L. D. Young, T. E. Socha
Comparison Of Methods Of Predicting Breeding Values Of Swine, J. W. Keele, R. K. Johnson, L. D. Young, T. E. Socha
Department of Animal Science: Faculty Publications
Best linear unbiased predictions (BLUP) using information from all known relatives; selection index using phenotype, full-sib average and half-sib average; and phenotypic deviation from contemporary group average were compared as methods of predicting breeding values for days to 100 kg and backfat. Swine records (n = 203,869) from five Hampshire, one Duroc and six Yorkshire herds were obtained from the Nebraska SPF Swine Accrediting Agency. Heritability values used to compute BLUP or index were either estimates based on within-breed offspring on parent regression or values recommended by the National Swine Improvement Federation (NSIF) guidelines. Within-breed estimates of heritability ranged from …
Effect Of Sex Ratio Of The Birth Litter On Subsequent Reproductive Performance Of Gilts, W. R. Lamberson, R. M. Blair, K. A. Rohde Parfet, B. N. Day, R. K. Johnson
Effect Of Sex Ratio Of The Birth Litter On Subsequent Reproductive Performance Of Gilts, W. R. Lamberson, R. M. Blair, K. A. Rohde Parfet, B. N. Day, R. K. Johnson
Department of Animal Science: Faculty Publications
Records on age at puberty from 1,555 gilts and total number of pigs born in litters of 1,187 gilts from the Nebraska gene pool population were used to evaluate the effects of uterine environment on subsequent reproductive performance. Independent variables were line, year, line x year, proportion of males in the birth litter (sex ratio), number born in the birth litter (fraternity size) and sex ratio x fraternity size. Sex ratio, fraternity size and their interaction influenced age at puberty (P < .01) but not number born (P > .2). Partial regression coefficients indicated that age at puberty tended to decrease as sex ratio increased, particularly …