Genetic analysis of lifetime performance and fertility traits in the pig breeds Large White, German Landrace and Pietrain.

摘要

The heritabilities and additive genetic correlations for the traits length of productive life, number of piglets born alive in total lifetime of the sow and number of piglets born alive in the 1st litter and in litters 2-10 were estimated using multivariate animal models for the pig breeds Large White (DE), German Landrace (DL) and Pietrain (PI). The data set analysed included 654 DE sows, 12.873 DL sows and 6.472 PI sows. The fixed effects in the model used were the age at first farrowing, mean number of days between consecutive farrowings and litter number of the 2nd to 10th litter. The additive genetic effect of the sow and the effects of herd-year-season-classes and the permanent environment of the sow during the 2nd to 10th litter were included as random effects. Heritabilities of the length of productive life estimated in trivariate and bivariate animal models were h2=0.19 and 0.17 in DE sows, 0.16 and 0.10 in DL sows and 0.22 and 0.20 in PI sows, respectively. The corresponding values for the trait number of piglets born alive in total lifetime of the sow were h2=0.37 and 0.18 (DE), h2=0.39 and 0.12 (DL) and h2=0.32 and 0.18 (PI), respectively. The estimates of the number of piglets born alive in the 1st litter were h2=0.19 (DE), 0.14 (DL) and 0.11 (PI), whereas the estimates for the number of piglets born alive in the litters 2-10 reached h2=0.18 (DE) and 0.16 (DL and PI). The additive genetic correlations between the different traits of lifetime performance and fertility were favourable in all breeds. This led to the conclusion that selection for fertility caused increasing length of productive life and higher lifetime performance at the same time. The additive genetic correlations between the length of productive life and number of piglets born alive in the 1st litter and the 2nd to 10th litter amounted to rg=0.57 and 0.77 in DE sows, rg=0.40 and 0.67 in DL sows and rg=0.15 and 0.55 in PI sows, respectively. The trivariate estimates for the additive genetic correlations between the different traits of fertility were rg=0.87 (DE), rg=0.80 (DL) and rg=0.68 (PI). The additive genetic correlations between the traits of lifetime performance were rg=1.00 in DE sows, 0.95 in DL and 0.96 in PI sows.