Study On The Influencing Factors Of The Reproductive Performance Of Sows In A Pig Farm In Sichuan And The Measures For The Purification Of Reproductive Diseases

The data of farrowing data were collected from 2015 to 2017 year.The data was sorted in EXCEL,the analysis of F test and pearson correlation of data compiled by using SPSS22.0,the calculation and selection index of EBV of litter core and backfat thickness was measured by NETPIG.The main results are as follows:1.There were significant differences in the reproductive performance of different varieties of American sow.Among them,the total number born(TNB),mummy fetus(MF),fetal death(FD),number born alive(NBA),primary litter weight(PLW)and birth weight(BW)were significantly different among varieties(P<0.05).The TNB(9.96),and NBA(8.58),BW(12.99kg)of Duroc were significantly lower than the York and Landrace(P<0.05).2.The TNB,NBA,BW,PLW of different parity have significant difference(P<0.05).The TNB and parity had significant correlation,York(r=0.287,P<0.01),Landrace(r=0.352,P<0.01)and Duroc(r=0.235,P <0.05).The NBA and parity also exist significant correlation: York(r=0.256,P<0.01),Landrace(r=0.305,P<0.01),Duroc(r=0.232,P<0.05).3.Hybridization can also cause the difference of reproductive performance.Y♂×Y♀,L♂×L♀ the TNB was significantly lower than that of D♂×LY♀ and D♂×YL♀,the NBA of Y♂×Y♀,L♂×L♀,L♂×L♀ was significantly lower than that of D♂×LY♀and D♂×YL♀(P<0.05),the different combinations and TNB had significant correlation(r=0.158,P<0.01),the different combinations and NBA showed a significant correlation(r=0.157,P<0.01).There were significant differences in NSP,BW and PMW among different combinations.4.There were no significant differences of the TNB,NBA and MF in the different mating season(P>0.05).The FD of the summer was significantly higher than the spring and winter about York pig(P<0.05).However,the FD in autumn of Landrace also significantly was higher than that in spring(P<0.05).5.We compared the delivery of sows using artificial insemination(AI)and deep insemination(DI).The results showed that total number of born(12.71±2.84),born alive litter size(11.54±3.02),number of healthy birth(11.17±2.73)and birth weight(1.65±0.29)with DI was higher than AI(P<0.05).6.Breeding could significantly affect the TNB of the estimate breeding value(EBV),the sire line index(SLI)and the dam line index(DLI).The NETPIG calculated to the results about SLI and DLI of York and Landrace.The results show that there was no significant change in the genetic value of EBV of the TNB and The EBV of day and backfat thickness was negative value.7.In order to control and purify the reproductive diseases in pig farms,we compared the antigen content and antibody content of PRRS,PR and CSF before and after immunization.The results showed that immunization is effective to control the infectious diseases of PRSSV,CSFV and PRV.