Herd specific effects of the ESR gene on litter size and production traits in Czech Large White sows

Abstract

The effect of PvuII polymorphism of the oestrogen receptor gene on litter size and production traits in a Czech Large White population (882 sows, 2 455 litters) was evaluated. Data were analysed by four four-trait animal models. The traits analysed were lifetime average daily gain in the field test, lean meat percentage, number of piglets born alive in parity 1 and number of piglets born alive in parity 2 and subsequent parities. The animal models differed in considering the herd-year-season effect as random or fixed and in including or not including the dominance effect. For each model two variants were calculated: the ESR effects were calculated either across herds or within herds. On the genetic level, no significant overall effects of the ESR gene were detected. The effects of the ESR gene within herds were mostly insignificant as well. There was a certain tendency for allele A to increase litter size in parity 1. Nevertheless, on the basis of the present knowledge, the use of the ESR gene for selection for litter size in the Czech Large White breed seems to be of questionable benefit and cannot be recommended.