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Increasing piglet weaning age while maintaining the reproductive efficiency of the breeding herd depends on the ability to stimulate sows to ovulate during lactation without reducing subsequent pregnancy rates and litter sizes. The aim of this study was to determine if a reduction in piglet suckling load, either prior to or immediately after mating in lactation, altered ovarian follicle development and increased embryo survival to day 30 of gestation.
Methods: Fifty-nine multiparous Large White x Landrace sows were allocated to one of three treatments; litter size maintained at 11 piglets (control); litter size reduced to seven piglets on day 18 of lactation (split wean); or litter size reduced to seven piglets at expression of lactation oestrus (oestrus split wean).
Results: The percentage of sows that expressed lactation oestrus did not differ between treatments (79.7 %) and split weaning had minimal effects on ovarian follicle development. Pregnancy rates were higher for split wean and oestrus split wean sows, compared to control sows. Embryo survival to day 30 of gestation was higher for split wean sows (73.7 %) compared with control (56.4 %) and oestrus split wean sows (49.5 %).
Conclusion: In summary, weaning a portion of the litter prior to mating in lactation improved pregnancy rates and embryo survival.
Weaver AC, Kind KL, Herde PJ, van Wettere WHEJ. Split weaning improves pregnancy rate and embryo survival in sows mated in lactation. Animal Reproduction Science. 2024; 263: 107440. https://doi.org/10.1016/j.anireprosci.2024.107440.