In order to provide more effective reference for pig producers, this article studied the effects of four non-geneticfactors, in different years, parity, mating month and delivery month, on the reproductive performance in Berkshire sow by measuring, recording, collating and analyzing the total number of births, number of births, number of deformities, number of still births and mummies, birth weight of the whole litter and the birth weight in common of a Berkshire sow on Weihong original breeding farm in Hunan. The study showed that with the passage of different years, the reproductive performa...
