Associations between Feed Intake of Growing Gilts, Lactating Sows and Other Reproductive or Performance Traits

The genetic and phenotypic associations between performance and feed intake traits of finished gilts (GFI), along with their subsequent reproductive performance and feed intake during lactation (LFI), were estimated using data collected from two maternal lines recorded under the same management system. Ad-libitum feed intake was heritable (h: 0.33±0.08) when recorded in post-finisher gilts or during lactation (h: 0.11±0.09). Genetic (ra) and phenotypic (rp) correlations between GFI and performance traits support the hypothesis that selection for reduced back fat (BF) and lower feed conversion ratio (FCR) are associated with a reduction in feed intake (ra: 0.36±0.11 and 0.79±0.11 for BF and FCR respectively). However, the correlations between GFI and measures of sow reproductive performance were lower (ranges: ra from -0.16 to 0.01; rp from -0.07 to 0.02). Current estimates of genetic and phenotypic correlations between GFI and LFI do not support the expectation of a positive association between these traits (ra: -0.26±0.33; rp: 0.05±0.04) although standard errors are large. More data are required to obtain accurate estimates of correlations between LFI and the other traits.