Shanghai Large White Pig Farm Type Score System And Genetic Parameter Estimation

Shanghai pig farm began to introduce large white pigs from France to carry out the overgroups and selection work since 2000.Because of the continuing breeding on reproductive traits and growth traits,large white maintained a good reproductive performance and growth speed.But because of small population size,and the introduction of margin less blood,so the progress in genetic improvement of body type score is relatively slow.The worse body type score also seriously restricted the economic benefits of pigs.Shanghai pig farm groups is trying to perform open breeding,strengthen body appearance,choose a balanced somatotypes of leg and hip fullness,limbs strong individual shape,and improve the superiority and perfection of the pig body appearance to meet the market demand.Therefore,Shanghai pig farm based on their own herds as the seed material,aimed at the body appearance of symmetry,limb hoof strong,abdominal line,good external genitalia of moderate size,taking into account the reproductive performance and the growth rate.All this works depend on the construction of scoring system and estimation of genetic parameters.Specific research contents and results are as follows:(1)construction of the body type score system: Shanghai pig farm construct body type score system score on the basis of the international company HYPOR,PIC,the United States breeding system evaluation method and the GPS software,and combined with the practice of Shanghai pig.Using the linear score,we constructs the scoring method of Shanghai pig farm from the pig hoof structure,abdominal line,external genitalia,as well as the overall coordination of the "Three emphases and one unification" pig conformation score.This work laid the foundation for estimating the genetic parameters of subsequent body shape score and and eliminating the gene underling hog disease.(2)estimation of genetic parameters of body type score: We estimated genetic parameters using restricted maximum likelihood(REML)statistical analysis model from ASReml-R on the score data.The results showed that: Shanghai pig farm hoof structure is moderate heritability and effective papilla,external genitalia,overall structure traits with high heritability.There was a positive correlation between body appearance traits,including forelimbs and department,hind side side and department related to the maximum(0.42);Therefore,the body shape determines the health and service life of the back-up pig,which is in line with the reasons for the elimination of the sows in the actual production.Based on the above research,we have constructed the body scoring system for Shanghai pig breeding farm,estimated the related genetic parameters,and laid a necessary foundation for further development of body physiognomy breeding.