The Relationship Between Backfat And Reproductive Traits In Large White Sows

Large white pigs are often used as the first female parent of the three-way hybrids,whose reproductive performance directly affects the efficiency of the production in the commercial pigs.In addition,the stages of sow backfat thickness can be reflected the sow’s body condition from the side,and the sow’s body condition directly affects the reproduction performance of the sow.In order to explore the optimal backfat thickness of sows in each stage,we selected growth and reproduction data from the Qingyuan Second Pig Farm of Qingyuan Pigs.The relationship between the backfat thickness of the sow and the reproductive traits was discussed.The data of backfat thickness and reproduction at each stage of the gestation period in the past two years were selected.The relationship between the backfat thickness and changes during the gestation period and the reproductive traits of sows in the primipara and sows were investigated.The results of the test showed that:(1)Back-testing of the sows is thinner(6.00~8.20 mm),the number of weak litters and mummies is higher.(2)There was no significantly difference in the reproductive performance between the backfat thickness at each stage in the first-born sows.(3)The backfat of multiparity sows before breeding as well as 28,56 and 80 days of gestation were 15 to 18 mm,15 to 22 mm,15 to 18 mm and 15 to 22 mm respectively,the reproductive performance was optimal,its number reached 12.06,12.06,12.44,and 11.95 respectively.When the weaning backfat was 15~18 mm,the sow had the best reproductive performance in the next fetus,and the number of the healthy cub reached 12.41.(4)The effect of changes in backfat on the reproductive performance of the sows with thin backfat(10~14 mm)was not significant during pregnancy.(5)When the variability of gestational backfat was less than or equal to 3 mm in the primiparous sows of moderate backfat(15~18 mm),and the backfat during lactation was more than or equal to 1 mm in multiparous sows and the change in gestational backfat was at-2~3 mm,the reproductive performance of the sows was the best,and the number of the healthy cub reached 11.39,12.18,and 12.13 respectively.(6)When the thicker backfat(19~22 mm) was more than or equal to 1 mm during lactation in the primiparous sows,the sows’ reproductive performancewas the best,and the number of the healthy cub reached 11.70.