CategoryAnimal Science - Breeding & Genetics
Date Full Report Received12/01/2010
Date Abstract Report Received12/01/2010
Funded ByIowa Pork Producers Association
The first purpose of this study was to determine the genetic and phenotypic correlations between maternal and post-weaning traits from a seedstock swine breeding system. The post-weaning traits examined included backfat (BF), percent lean (PCL) and days to market (D100), all adjusted to 100kg live weight. The strongest phenotypic correlation was between PCL and BF at -0.72 (P<0.05). The genetic correlations between LSY and each of the post-weaning traits (BF, PCL, and D100) were 0.02, -0.16, and 0.26 (P>0.05), respectively. The correlations between litters per sow per year and post-weaning traits suggest that selecting based on litters per sow per year should not negatively impacting the post-weaning traits in the herd. The direction of the correlation between number born alive and post-weaning traits was non-significant from this study. The second purpose of this study was to determine the genetic control of LSY and the relationship between individual sires breeding values (BV) for litters/sow/year (LSY) and progeny farrowing rate means. The heritability of LSY from this study was found to be low (<0.15). This suggests that BLUP based breeding value estimation must be used to make genetic progress in LSY. The correlation between the LSY BV and the sire progeny mean farrowing rate was 0.21 for those sires who had 10 or more daughters. The correlation between LSY BV and sire progeny mean for farrowing rate suggests that selecting for LSY could positively impact farrowing rate, and thereby reduce non-productive sow days.