Studies On The Genetic Parameters Of Major Traits And Growth Discipline In Large White Swine

In order to study the growth and developmental mechanism and genetic parameter estimation among main traits in Yorkshire,this research to made efforts on four aspects:production performance,growth curve,growth and development traits and main multiply traits.The result is as follows:(1)Determines the boar 425 and swine 463 heads.The boar's newborn,in 20 days,in wean(28 days),in 6 months body weight respectively is 1.56kg,7.78kg,10.47kg,94.17kg;the swine body weight in these four periods respectively is 1.32kg,7.52kg,10.01kg,85.68kg;the body measurement indexⅠand body measurement indexⅡof adult boar and swine respectively is 187.5,83.4,20.5,113.3;the TNB, NBA and number of weaned piglet respectively is 10.68,9.85 and 9.30 heads, reproduction rate is 92.3%and survival rate is 94.4%;in lactation performance,the average milk producton of suckling swine in 5,10,15,20,25,28 day respectively is 8.64kg,11.32kg,13.20kg,13.85kg,14.45kg and 13.96kg.(2)Separately carries on the fitting using Logistic and the Gompertz equation to 200 boar's growth curve.The result shows that both of the two equations can fit the boar's growth curve well,but considered the R~2 and the run condition,the Logistic equation suits in fits the boar's growth curve.The boar's Logistic and the Gompertz equation growth curve inflexion respectively is(125.36,72.11)and(119.02,66.28).(3) Choosing the growth and development performance measure records of boar 425 and swine 463 heads.It includ the body length,body high,body weight, chest circumference(CC) and HG in 6 months,using genetic parameter modal to determine the growth and developmental traits.The result is that body weight variation coefficient is about 10%,and the variation coefficient of body length,body high,CC and HG is also between 3%to 5%;the heritability of body high and HG is low,but the heritability of body weight is relative high;the genetic correlation of body length,body high,body weight,CC to HG in 6 months is in the range of 0.486-0.852,all of them achieved the exterme significance level(p＜0.01).And the genetic correlation of body weight to CC and HG is high.(4)To calculate the product and suckling performance records of 240 Yorkshire swine.In phenotype parameter,the birth weight is low,is only 13.29%;other traits are relative high,is in the range of 21.77%-24.77%;the heritability among main productive traits is between 0.04 and 0.16,except NBA,the heritability difference of other traits are quiet(p＞0.05),the heritability of all the traits are below 0.3,it belongs to low heritability.Except the genetic correlation of LWB to TNB and NBA (respectively is-0.482 and-0.593),birth weight to TNB and NBA(respectively is -0.454 and-0.565) are negative number,other traits are all positive genetic correlation(0.103-0.871),the genetic correlation of NBA to TNB is the highest among the total,it is 0.871.In Phenotypic correlation among multiply traits,the correlation of LWB to birth weight is low(0.1138),but the coefficient correlation of LWB to other genetic traits are all achieve the extreme significance level(P＜0.01),the coefficient correlations are in the range of 0.4023-0.7356.