体型评分性状的遗传分析及其在选种中的利用

The Genetic Analysis of Type Score Traits and It's Application to Pig Breeding Program

本研究旨在围绕体型评分性状,探讨其与生产性状的遗传联系,并浅析其在生产中如何有效利用。通过比较分析了不同体型评分下,生产性状表型的差异;同时分别利用单/多性状线性模型和阈模型对大白猪体型评分性状进行了遗传参数估计,并计算了体型评分性状与部分主要生产性状之间的表型和遗传相关以及排名的秩相关。结果表明:随着体型评分的升高,达100 kg体重日龄与100 kg体重背膘厚均逐渐降低,差异极显著(P<0.01),头胎产仔数差异不显著(P>0.05);单性状和多性状线性模型体型评分遗传力分别为0.03和0.04,阈模型遗传力为0.21;此外,体型评分与头胎产仔性能呈强的正遗传相关,而与非头胎产仔性能呈弱相关,与生长性状呈强的负遗传相关;最后,秩相关结果显示,单一通过性状EBV排名来选种不可靠,但排名靠前个体体型评分均值在8.0左右,提示应综合体型评分和育种值排名来选种。

The objective of this study was to analysis the relationship between of type score traits（TST） and production traits and to discover it＇s application to pig breeding program. First, we compared the differences among production traits under different type score traits; Then the genetic parameter of TST was estincaed, utilizing single/multi traits linear model, and the phenotypic, genetic and rank correlation between type score and production traits was calculated. The results showed that along with the increase of type score, the age at 100 kg live weight（AGE） and backfat at 100 kg live weight（BF） were significantly decreased（P〈0.01）,the total number of first born（TNFB） was not different（P〉0.05）; The heritabilities of TST were 0.03,0.04 and 0.21 for single, multi traits linear model and threshold model, respectively. Furthermore, the genetic correlation between TST and TNFB, none TNFB and growth traitsare strong positive, weak and strong negative, respectively. At last, the rank correlation result shows that it＇s unreliable to select by followed the rank of EBV only. Otherwise, the average score was 8.0 between high rank individuals, implying that its reliable to type score first and then according the ranking of EBVs.