title: Genetic heteroscedasticity of teat count in pigs.
abstract: The genetic improvement in pig litter size has been substantial. The number of teats on the sow must thus increase as well to meet the needs of the piglets, because each piglet needs access to its own teat. We applied a genetic heterogeneity model to teat counts in pigs, and estimated a medium heritability for teat counts (0.35), but found a low heritability for residual variance (0.06), indicating that selection for reduced residual variance might have a limited effect. A numerically positive correlation (0.8) was estimated between the breeding values for the mean and the residual variance. However, because of the low heritability of the residual variance, the residual variance will probably increase very slowly with the mean.
authors.affiliation: Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.|School of Technology and Business Studies, Dalarna University, Falun, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Felleki
authors.affiliation: Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: N
authors.initials: N
authors.lastname: Lundeheim
mesh_terms: D000818:Animals; D001947:Breeding; D019295:Computational Biology; D005260:Female; D014644:Genetic Variation; D008321:Mammary Glands, Animal; D015233:Models, Statistical; D013552:Swine / Q000033:anatomy & histology* / Q000235:genetics*
keywords: Quantitative genetics; genetic heterogeneity of residual variance; pig; teat count