Re-serviced females on commercial swine breeding farms

Abstract

The objectives of this study were to observe subsequent reproductive performance of re-serviced females by the number of services within a parity, to measure mean days to re-service and culling intervals, to determine lifetime performance in re-serviced gilts, and to investigate re-serviced females across parities on commercial farms. Reproduction records on 539 U.S.A. farms were used to observe re-serviced females by the number of service groups at the herd level. Farrowing rate decreases by approximately 10%, and re-service occurrence increases by approximately 5% for each increase in the number of services increase within a parity group (P<0.05). Only in parity 0 to 2 groups, average pigs born alive at subsequent farrowing in the second or later service groups were greater than in the first service group (P<0.05), but in parity >or=3, the third or later service groups produced fewer pigs born alive than the other service groups (P<0.05). Lifetime performance and re-service events were observed in 39945 individual females on the 149 selected farms that had complete 5-year records. Means of days to re-service, first-mating-to-culling intervals in gilts and weaning-to-culling intervals in sows were 46.3 days, 95.2 days, and 48.2 days, respectively. Re-serviced gilts had longer NPD (>50 days), a lower parity at culling (>0.5) and fewer lifetime pigs born alive (>2 pigs) than non-return gilts (P<0.05), but no difference in average pigs born alive per parity was found between re-serviced gilt groups and non-return gilts. Of 19677 re-serviced females, 35.6% had two or more re-services across parities in pig life, 10.6% had 3 or more re-services, and 1.95% had four or more re-services. Accurate estrus detection with a boar and improved mating techniques on re-serviced females are suggested to improve herd productivity.