PUBERTY, POST-WEANING ESTRUS AND ESTROUS CYCLE LENGTH IN YORKSHIRE AND LACOMBE SWINE

Abstract

Age at puberty in gilts and the number of days from weaning to estrus were determined on 132 gilts and 370 primiparous sows. The average age at puberty was 197.5 ± 1.8 (SE) days, in a range of 141 to 254 days. In this study, Yorkshire sows averaged 5.5 ± 0.3 days and Lacombe sows 14.3 ± 0.8 days to estrus after weaning (P < 0.001). In the first week after weaning, 90.5% of the Yorkshire sows and 48.0% of the Lacombe sows returned to estrus. One Yorkshire sow (0.5%) and 35 Lacombe sows (20.2%) failed to show estrus by 28 days after weaning. Yorkshire females had an average estrous cycle length of 21.0 ± 0.2 days, and Lacombe females 21.7 ± 0.1 days (P < 0.05).