Impact of hyper-prolific population generation on the reproduction of sows in multiplication herds

Abstract. The aim of this study was to evaluate the impact of higher selection pressure used in hyperprolific population on the reproduction of subsequent generations breed in a multiplication herd. Information on 539 litters of 178 ancestors of purebred sows from both hyper-prolific and normal population was included. Higher selection pressure particularly on litter size and teat number was applied in the hyper-prolific population. Differences between total number of piglets born, number of piglets born alive or number of piglets weaned were neither observed on the 1st only nor on the 1st to 5th litters. Likewise, no effect on the age of sows at the first parturition and number of insemination per pregnant had been found. A significant response on selection was determined only for teat number. The descendents of hyper-prolific population had about 0.37 teats more than sows of normal population. The results suggest that to achieve desired litter size in multiplication herds the selection criteria should be revised and higher focus should be put on the prolificacy, particularly on the litter size than on the traits with high heritability like production traits.