Late Gestation Health Status is Correlated with Lactation Outcomes for Sows

Gilts and sows from two nucleus farms (N=1103) were recorded after transfer to the farrowing shed for a range of health-related traits and subsequent lactation outcomes. Traits recorded pre-farrowing included fight lesions (FIGHT), caliper score (CAL), udder condition (MAST), haemoglobin level (HB), respiration rate (RESP), rectal temperature (RECT) and feed refusal before farrowing (FRBF). Lactation outcomes included the number of weaned piglets (NWEAN) and lactation failure (LFAIL). The highest heritabilities (h2) were estimated for CAL (0.34±0.08), FRBF (0.21±0.08) and RESP (0.20±0.09), while the remaining traits were lowly heritable. Antagonistic genetic (rg) and/or phenotypic (rp) correlations were estimated for NWEAN with FRBF (rg: -0.36±0.30; rp: -0.10±0.03) and for CAL with HB (rg: 0.33±0.41; rp: 0.15±0.03). The absence of pre-farrowing mastitis was associated with higher NWEAN both genetically (-0.74±0.30) and phenotypically (-0.05±0.03), indicating that selection for healthy udder led to increase in NWEAN. Sows with higher levels of HB and fewer feed refusals had increased NWEAN. Non-zero heritabilities demonstrate that health-related traits have a genetic component, but evaluation of their potential use as selection criteria to improve lactation outcomes for sows requires additional data to obtain more accurate estimates of genetic correlations.