Genetic Evaluation And Genetic Parameter Estimation In Largewhite Pigs Using Animal Model BLUP And REML

This paper presents the estimates of variance components and genetic parameters for 13 reproduction traits of large white pigs using animal models by derivative-free restricted maximum likelihood. The fixed effects, the random litter effects and the animal additive genetic effects were calculated. Animals were ranked according to their BLUP -EBVS to provide information for selection. The phenotypic and genetic trends of the reproductions traits by year were analyzed.The study uses three models to estimate the genetic parameters of thirteen reproduction traits of large white pigs.The result presents that Model Ⅲ is better than model Ⅰand modelⅡ.Because the residual variance is the least.It is thinked that it is wise to estimate the variance and genetic parameters of reproduction trait using Model Ⅲ.The result suggests that the heritability estimates of total number of piglets born, number of piglets born alive, birth litter weight, birth weight, 21-day litter weigh, 21-day weight, 21-day litter size, 60-day weaning litter size, 60-day weaning litter weight, 60-day weaning weight, 35-day weaning litter size, 35-day weaning litter weight, 35-day weaning weight were 0.15,0.11,0.14,0.26,0.07,0.15,0.05,0.1,0.07,0.13,0.05,0.31,0.1;the additive maternal genetic effects of these reproduction traits were 0.06,0.08,0.01,0.02,0,0.04,0.04,0,0.01,0.08,0.01,0.21,0, and the correlation between the additive direct genetic effects and the additive maternal genetic effects were -0.1,-0.62,-0.98,-1,-0.94,-1,-0.3,1,1,-0.93,-1,-1,-1。And common litter environment effects ranged from 0.0000000264136 to 0.0307697.The result shows that TNB,NBA,LBW had the same regular pattern influenced by parity effect.The first parity was low,then ascending,the 5th,6th parity were the highest,then descending.W60,LW60,S60 showed the same regular pattern.The parity effect of LW35 was increasing with the parity changes larger.BW,LW21,W21,S21 were not influenced by parity.The phenotypic trends of reproductive traits were descending.About genetic trends,NBA,LBW,S21,LW21,S60,LW60 were ascending,W21,W60 were descending,TNB,BW were steady.And all of the variety were small.