Effects Of Parities And Farrowing Seasons On The Reproductive Performance Of PIC Sows

In order to study the PIC sow reproductive performance with parity or delivery season,selected production records from 3 PIC parents generations breeding farms of an agricultural corporation of Shaanxi province from 2014 to 2015,statistics the reproductive performance in different parities and seasons,then make one-way analysis of variance and LSD multiple comparisons,the results showed:1.Percent repeat services decreased with the parities increased,Entry to 1st service interval and percent of served bred 7 days were unrelated with parity,and they were corrected with sow’s physiology and health condition.Total born per farrow and live born per farrow of the 1st to seventh parity were higher and that of the eighth parity was the lowest.The Litters/mated female/year of eighth parity was significantly lower than that of the 1st to seventh parity.Pigs weaned in period of eighth parity was the lowest and significantly lower than that of the 1st to sixth party.PSY was progressive increased to the hightest from 1st to 3rd parity,and that of the eighth parity was significantly lower than that of the 1st to sixth parity.The results can act as the basis of weed out sows from eighth parity.Death rate of the eighth parity was significantly higher than that of the 1st to sixth parity,it showed that it had tremendous relationship between death rate and parities.2.Percent repeat services,entry to 1st service interval,percent of served bred by 7 days,total born per farrow,live born per farrow,%stillborn,farrowing rate,pigs weaned in period and avg weight/weaned pig were all unrelated with delivery season.The %Mummies in summer was significantly higher than that in other seasons.3.From the results,the conclusion as follow:The reproductive performance of the eighth parity was significantly different with that of other parities,it can act as the basis of weed out sows from eighth parity.There was no obviously influence between reproductive performances and seasons except the %Mummies.the high temperature stress had an obviously influence to generate mummies,it can lower it through cooling in summer.