Analysis of periparturient risk factors affecting sow longevity in breeding herds

The association of periparturient risk factors with sow longevity and the validity of sow removal decisions made during the periparturient period were analyzed. Data pertaining to 2066 sows from a commercial breeding herd from the US Midwest were used in this study. The likelihood of removal from the herd within 35 d post-farrowing decreased with a younger parity, the absence of lameness or other health problems, a higher lactation feed intake (LFI) and a greater number of live-born piglets (P <0.05 for all). A greater number of piglets born alive, the absence of lameness and a younger parity lowered (P <0.05 for all) the likelihood of removal of sows from the herd before the next parity. The number of piglets born alive was higher (P <0.05) among sows without any health problems during the previous periparturient period. A greater (P <0.05) number of sows that were retained without any health problems during the periparturient period farrowed. More sows (P <0.05) retained with health problems during the periparturient period were culled compared with sows retained without health problems during the periparturient period. In summary, periparturient factors such as LFI, the incidence of lameness or health problems, as well as sow-level characteristics such as higher parity and fewer piglets born alive predicted the removal of a sow from the breeding herd. Sows retained with periparturient health problems had reduced longevity and fewer live-born piglets, and fewer such sows had another farrowing.