长白和大白猪主要生长性状的遗传参数估计

旨在分析母猪的出生年份、出生季节、初生重、开测日龄等固定效应对长白、大白猪主要生长性状的影响，并对目标生长性状进行遗传参数估计（遗传力、遗传方差、表型相关和遗传相关），为猪的遗传改良提供基本依据。本试验利用GLM模型分析试验猪群（398头长白猪和1 176头大白猪）的固定效应对猪生长性状的影响，并采用多性状动物模型对目标性状进行遗传参数估计。目标生长性状包括达100 kg体重日龄（age to 100 kg，AGE）、达100 kg背膘厚（backfat to 100 kg，BF）、100 kg平均日增重（average daily gain to 100 kg，ADG）。研究表明，在大白和长白猪中，猪的出生年、出生季、初生重以及开测日龄对生长性状均具有极显著的影响（P<0.001）；长白猪的AGE、ADG和BF的遗传力分别为0.321、0.327和0.324，大白猪对应性状的遗传力分别为0.454、0.469和0.408；长白猪的ADG和AGE之间的遗传相关、表型相关分别为-0.990、-0.995，大白猪的ADG和AGE之间的遗传相关、表型相关分别为-0.993、-0.998，均呈现较强的负相关。长白、大白猪的生长性状（AGE、ADG、BF）均属于中等遗传力性状，其出生年份、出生季节、初生重和开测日龄对猪的生长性状影响较大。在遗传参数估计分析时，提高样本数量并提升表型数据质量，可以增加遗传参数估计的可靠性。本研究中的生长性状遗传参数估计结果较为可靠，可为后续的遗传改良提供参考。

Estimation of Genetic Parameters of Main Growth Traits in Landrace and Large White Pigs

This study aimed to predict and analyze the effects of fixed effects such as the year of birth, birth season, birth weight and the age at the beginning of test on the growth traits of Landrace and Large White pigs, and calculate the genetic parameter estimated values (heritability, genetic variance, phenotypic correlation, and genetic correlation), which would provide a basic reference for pig genetic improvement. In this experiment, the GLM model was used to analyze the effects of fixed effects on growth traits in the experimental pig herd (398 Landrace pigs and 1 176 Large White pigs), and a multi-trait animal model was used to perform the genetic parameters estimation to the target traits. The target growth traits included age to 100 kg (AGE), backfat to 100 kg (BF), and average daily gain to 100 kg (ADG). The study showed that, in Large White and Landrace pigs, the year of birth, birth season, birth weight, and the age at the beginning of test all had extremely significant effects on growth traits (P<0.001); The heritability of AGE, ADG and BF were 0.321, 0.327 and 0.324 in Landrace pigs, the heritability of the corresponding traits in Large White pigs were 0.454, 0.469 and 0.408, respectively. The genetic correlation and phenotypic correlation between ADG and AGE in Landrace pig were -0.990, -0.995, respectively; the genetic correlation and phenotypic correlation between ADG and AGE in Large White pigs were -0.993 and -0.998, respectively, showing a strong negative correlation. The growth traits (AGE, ADG, BF) of Landrace and Large White pigs were the traits with medium heritability. The year of birth, birth season, birth weight, and the age at the beginning of the test have a greater impact on the growth traits of pigs. When genetic parameters are estimated and analyzed, the reliability of genetic parameter estimation can be increased by increasing the number of samples and improving the quality of phenotypic data. In this study, the estimation results of the genetic parameters of growth traits are relatively reliable and can provide references for subsequent genetic improvement.