Behavioural patterns and progesterone, cortisol and prolactin levels around parturition in European (Large-White) and Chinese (Meishan) sows

Abstract

The behaviour of seven Large-White (LW) and seven Meishan (MS) sows was monitored continuously on video from Day 111 of gestation to 24 h postpartum (Experiment 1). In a second experiment, plasma levels of progesterone, cortisol and prolactin were measured in six LW and six MS sows from Day 105 of gestation to 48 h postpartum. All the sows were tethered between Days 100 and 107 of gestation and penned on a concrete floor with (Experiment 1) or without (Experiment 2) straw bedding. In both breeds, activity levels and posture changes increased as parturition approached. Before parturition, the only differences between the two breeds occurred during the last 24 h: MS sows spent more time exploring the floor (36% vs. 10% of total time) and LW sows lay more often on their bellies (26% vs. 13% of lying time). During parturition, the total lying time was high and significantly greater in LW (98%) than in MS sows (90%). During the first 24 h after farrowing, behaviour was similar in both breeds with animals lying most of the time (> 90%). The time spent in nursing activities was also the same in both breeds. During the first day of their life, total resting time was similar in MS and LW piglets; nevertheless resting behaviour occurred more often at the udder in MS piglets. Time spent active at the udder was not affected by the breed. Plasma concentrations of cortisol and prolactin (Experiment 2) increased during the 24 h prepartum, reached a peak prior to parturition and decreased thereafter. The cortisol peak tended to occur earlier in MS than in LW sows, while the prolactin peak occurred at the same time in both breeds. Progesterone levels remained high until 48 h prepartum and decreased thereafter. Cortisol and prolactin levels were not affected by breed, nor by the sampling hour (08:00 h vs. 14:00 h vs. 20:00 h) but progesterone levels were higher in MS than in LW sows. This study suggests that the good reproductive performance of the MS breed could partly be related to the behaviour of the sow and her litter after parturition.