Abstract

This study was conducted to assess the factors that affect pig litter size, proportion of live pigs at birth, number of inseminations per conception, and efficiency of artificial insemination. The main factors assessed were sow breed (n = 2), sire breed (n = 3), sow parity (n = 7) and insemination method (n = 2). The sow breeds used were Landrace, LL (n = 27) and Landrace × Pietran crossbreds, LP (n = 37); boar breeds used were Landrace (LL), Pietran (PP) and Landrace × Pietran crossbreds (LP). Sows were randomly inseminated either by boar or artificially, with semen freshly imported from Belgium to Rwanda. Landrace (LL) sows had significantly smaller (P<0.05) litter sizes at birth (9.04±0.72) compared to LP sows (11.49±0.45). On the other hand, the litter size for LL (9.04±0.58) and LP (11.49±0.67) sires did not differ, while PP sires had the highest (P<0.05) litter size (13.37±1.43). Interestingly, the method of insemination, whether use of a boar or artificially did not (P>0.05) affect the number of inseminations per conception, litter size, and proportion of piglets born live. Sow parity was found to have a linear relationship with a mean litter size at birth of 6.9±0.43 piglets for primiparous sows and 15.2±1.12 piglets for a sow of parity 7. However, the number of piglets born dead increased with parity, peaking at 3.0±0.66 (parity 7), while it was only 0.2±0.2 for parity 1. Therefore, the LP crossbred sows and Pietran sires are recommended. Artificial insemination should be promoted since it performed as well as natural insemination but provides other advantages such as African swine fever and inbreeding prevention, and avoids boar management costs.  

Key words: Breeding, genetic merit, performance, Pietran, pigs.