Estimation Of (Co) Variance Components And Genetic Parameters For Sow Longevity

Sow longevity(SL)is an essential trait which plays an important economic role in pig production.Improving the SL can reduce renewing and corresponding costs,so that the pig producer profits increase.Sow longevity is a sophisticated trait and can be defined differently on the purpose of the study.In this study,the author focused the eliminative parity(EP)as Main measure traits,and the age of elimination(SE)and Total number of live births(TNB)as a comparison to measure the SL in many aspects.In this study,the author adopted the Duroc,Landrace and large white production data of 3 varieties of a total of 4564 sows from 2009 to 2017 of a pig breeding farm in Fujian province.Using DMU software,the variance components,heritability and genetic correlation were estimated by single/multi-character animal model.R software was used to analyze the fixed effect of EP,AE and TNB,and analyze the trend of genetic elimination of parity.The main results are as follows:1.In Duroc sows,the number of EP,AE and TNB were 3.42,583.96 and 26.39 respectively.In Landrace sows,the number of EP,AE and TNB were 4.02,666.70 and 40.79 respectively.In Large White sows,the number of EP,AE and TNB were 3.62,698.71 and 36.05.2.In Duroc,Landrace and Large White sows,using multiple trait model to estimate the heritability of EP were 0.11,0.10 and 0.28 respectively.The heritability of AE in these three species were 0.09,0.12 and 0.12.The heritability of TNB in these three species were 0.19,0.09 and 0.28.3.The phenotypic correlation of estimation among these three traits in Duroc,Landrace and Large White Sows range from 0.91 to 0.98,the genetic correlation estimates in the range of 0.92 ~ 1.The phenotypic correlation of these traits show a higher genetic correlation.4.The year had a significant impact on three traits of three varieties(P < 0.001).The seasonal effected the EP significantly(P < 0.01)of Large White Sows,while impact on the AE and TNB significantly(P < 0.05).In duroc and large white sows,the seasonal have no effect on these three traits.5.Ep presented a positive trend on the genetic inheritance.Conclusion:In the large white sows,the eliminative parity(EP)and the total number of live births were medium heritability,while other properties were low heritability and had higher genetic correlation.This decided year can be an optimal factor for three traits,which can be used to select breeding trait and improve the sow utilization years.