Behavior and performance in primiparous sows of two Min pig hybrid breeds in outdoor housing systems

When sows and their litters are kept outdoors, the maternal ability, including maternal behavior, is very important for piglet health and survival. The aim of this study was to compare part of maternal behavior and performance in primiparous sows of two different conventionally bred Min pig hybrid breeds kept in outdoor housing systems. Damin sows (Large White×Min pig sows, n=21) and Changmin sows (Landrace×Min pig sows, n=21) were farrowed in individual pens. Sows’ postures (lateral, ventral, standing and sitting), changes of posture (lateral recumbency to other postures, ventral recumbency to other postures, standing to lying and sitting to lying), nursing behavior (duration and frequency of nutritive nursing, proportion of nursing terminated by the sow) and proportion of time spent outside the farrowing huts were observed by video for 72h after parturition and from 07:00 to 09:00h and 13:00 to 15:00h on the third and 6th day of each week from the 2nd to the 4th week after parturition. The duration of parturition, farrowing interval, number of live piglets, number of stillbirths, birth weights of the litters, number of piglet deaths during the first 3 days postpartum, number of piglet deaths from the 4th day postpartum to weaning, weaning weights of litters, and estrus interval of sows were compared between the two breeds. The two breeds showed no differences in postural behavior, changes of posture, nursing behavior and proportion of time spent outside the farrowing huts by the sows. The duration of parturition (P=0.043) and farrowing interval (P=0.032) were significantly higher in Damin sows than in Changmin sows. Birth weights (P=0.010) and pre-weaning weights (P=0.022) of the piglets were lower in Damin sows than in Changmin sows. Other performance parameters did not differ between the breeds. In conclusion, we understand that the high temperature did not have bad effects to the performance of two Min pig hybrid breeds in the summer, compared with other results, the two Min pig hybrid breeds may have a certain advantage in lateral recumbency during early lactation and piglets mortality. This may provides valuable information about choosing the reasonable outdoor breeds in the future.