Influence of inter- and intra-breed mixed semen on the fertility of sows

The effect of between and intra breed mixing of semen on the fertility had been studied in two trials, In trial one 128 sows were inseminated by either semen of one boar or by a mixture of semen of boars from two different breeds Pietrain (Pi), German Landrace (DL), Belgian Landrace (LB) and/or German Edelschwein (DE) and a mixture of all four breeds. The pregnancy rate of sows inseminated by mixed semen was 19.5% higher than inseminated by only one boar (p less than or equal to 0.05). There was no significant influence on the litter size at birth. The birth-weight of the piglets produced with mixed semen by the breeds Pi and LB was significantly higher than that of the other crosses. In trial two the mixed semen of Pietrain boars had been compared with its pure semen. Additionally the results produced by the boars of the farm (natural service) had been compared. There was a trend, that mixed semen produced better fertility results than semen of single boars. No differences in the within-litter-variability of the 3-week-weight between the two different insemination types have been found.