Effects of lactation length on weaning-to-first-service interval, first-service farrowing rate, and subsequent litter size

JWM, MSC: University of Georgia, Livestock Poultry Building, University of Georgia, Athens, Georgia, 30602-2771; DR: H330 Veterinary Medicine, University of Georgia, Athens, Georgia, 306022771 search has shown that in mature sows, maternal recognition of pregnancy is achieved approximately 10–13 days after the onset of estrus and subsequent mating.5 Furthermore, embryonic implantation into the uterine wall appears to be accomplished approximately 13–17 days post-estrus.5 Since the uterine environment appears to be ready to maintain pregnancy at 21–28 days postpartum,6,7 theoretically, a combined period of lactation length plus weaning-to-service interval as short as 4–8 days may be sufficient to allow a normal reproductive cycle to continue in mature sows. However, previous research does not address any potential differences between mature and first-parity sows. In this study, data from commercial swine producers using the PigCHAMP® recordkeeping system were used to examine the effects of lactation length on weaning-to-first-service interval, first-service farrowing rate, and first-service litter size in commercial sows of differing parities.