The Effect of the Gestation Period on the Breeding Performance of Large White Sows

The experiment used 200 litters of pigs which were chosen at random from 814 litters of Large White sows in the year of 2000 at a breeding pig farm in Jiangxi Province. DPS software was used to deal with the data. The pigs were divided into 4 groups according to their gestation periods: below 112 days, 113 to 115 days, 116 to 118 days and over 119 days. Several characters were analysed such as the total amount of piglets born, the amount of living piglets born, the birth weight of each piglet, the total birth weight of each litter, the amount of piglet weanling, the total weanling weight of each litter, etc. The results showed: with the prolongation of the gestaton period, the total amount of piglets born and the amount of living piglets born were reduced progressively (P0.05); but the birth weight of each piglet, the birth weight of each litter, the amount of piglets weanling, the weanling weight of each piglet and the weanling weight of each litter showed a trend of increase. The results of the relevance analysis showed:the gestation period is at weak negative relevance with the total amount of piglet birth and the living piglet birth, and at weak positive relevance with the total birth weight of each litter, the total weanling weight of each litter and the amount of piglets weanling.