Abstract

The aim of this study was to evaluate the effect of crossbreeding pure breeds on reproductive traits in pigs.The study was conducted on 2,431 record concerning reproductive traits of four pure breeds (large yorkshire (LY), swedish landrace (SL), duroc (D) and hampshire (H) and their reciprocal F₁ crosses. Data processing method was by the least squares for testing in animal adapted and introduced Harvey (1990). The results indicated improvement of reproductive traits by crossing pure breeds. The improvements were more pronounced in three way crossing and back way crossing. By crossing breeds, the number of live births and weaned pigs increased while the number of still born piglets decreased compared to pure breeds.Differences in terms of fertility between pure breeds can be successfully used by crossing selected (specialized) or race lines. Heterosis effect was manifested in reproductive traits, depending on the choice of crossing scheme involving one of three types of heterosis and breed selection for cross.

Key words: Pigs, litter size, crossing, heterosis effect.