Realized effect of different selection criteria applied in breeding herds on performance in multiplier herds

Different selection pressure on the litter size and growth performance traits has been applied on two subpopulations of Czech Large White sows (hyperprolific or normal). About 1933 farrows of 614 Czech Large White sows were included. The hypothesis that progeny of sows from hyperprolific subpopulation breed in multiplier herds have higher litter size traits was tested. Effects on the growth performance traits are reported so. Though the applied selection pressure on the number of functional nipples was low, these traits have remarkably increased in the HP subpopulation. Likewise, both studied growth performance traits reacted positively on the selection pressure and the differences between populations were highly significant. Surprisingly, no significant differences in litter size traits were found either in the first or in the first to fifth parity. The results outlined that the selection criteria applied in the breeding herds can efficiently increase the traits with middle or high heritability coefficients in multiplier herds. However, the selection seems rather non effective as far as the litter size traits are concerned, as the heritability coefficients of these are low and hence are influenced by crossbreeding. Using of auxiliary selection traits should be therefore considered for improvement of economic efficiency of multiplier herds.