Non-linear associations were found between litter size and sow survival to the next parity

Application Number of piglets born alive showed positive or no phenotypic associations with sow survival to subsequent parities. This implies that high litter sizes did not have detrimental effects on sow longevity, and both can be improved.
Introduction Procedures using commercially available test antigens have been developed to assess the immune competence phenotype of pigs (Harper et al., 2017), Improving sow longevity is necessary for both economic importance and welfare concerns. But, sow longevity is a difficult trait to select for because it can only be measured at the end of a sow's life. Number born alive (NBA) was positively associated with sow longevity and it was suggested as an early indicator trait for sow longevity (Engblom et al., 2016). However, non-linear associations between NBA and sow survival were not explored. This study aimed to investigate whether a larger NBA continuously favoured sow survival to subsequent parities.