College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China.
Key Laboratory of Meat Sheep Genetic Breeding of the Ministry of Agriculture and Rural Affairs, Hohhot 010018, China.
Yi Chuan. 2024 May 20;46(5):421-430. doi: 10.16288/j.yczz.24-036.
Inner Mongolia cashmere goat is an excellent livestock breed formed through long-term natural selection and artificial breeding, and is currently a world-class dual-purpose breed producing cashmere and meat. Multi trait animal model is considered to significantly improve the accuracy of genetic evaluation in livestock and poultry, enabling indirect selection between traits. In this study, the pedigree, genotype, environment, and phenotypic records of early growth traits of Inner Mongolia cashmere goats were used to build multi trait animal model., Then three methods including ABLUP, GBLUP, and ssGBLUP wereused to estimate the genetic parameters and genomic breeding values of early growth traits (birth weight, weaning weight, average daily weight gain before weaning, and yearling weight). The accuracy and reliability of genomic estimated breeding value are further evaluated using the five fold cross validation method. The results showed that the heritability of birth weight estimated by three methods was 0.13-0.15, the heritability of weaning weight was 0.13-0.20, heritability of daily weight gain before weaning was 0.11-0.14, and the heritability of yearling weight was 0.09-0.14, all of which belonged to moderate to low heritability. There is a strong positive genetic correlation between weaning weight and daily weight gain before weaning, daily weight gain before weaning and yearling weight, with correlation coefficients of 0.77-0.79 and 0.56-0.67, respectively. The same pattern was found in phenotype correlation among traits. The accuracy of the estimated breeding values by ABLUP, GBLUP, and ssGBLUP methods for birth weight is 0.5047, 0.6694, and 0.7156, respectively; the weaning weight is 0.6207, 0.6456, and 0.7254, respectively; the daily weight gain before weaning was 0.6110, 0.6855, and 0.7357 respectively; and the yearling weight was 0.6209, 0.7155, and 0.7756, respectively. In summary, the early growth traits of Inner Mongolia cashmere goats belong to moderate to low heritability, and the speed of genetic improvement is relatively slow. The genetic improvement of other growth traits can be achieved through the selection of weaning weight. The ssGBLUP method has the highest accuracy and reliability in estimating genomic breeding value of early growth traits in Inner Mongolia cashmere goats, and is significantly higher than that from ABLUP method, indicating that it is the best method for genomic breeding of early growth weight in Inner Mongolia cashmere goats.
内蒙古绒山羊是经过长期自然选择和人工选育形成的优良畜种，目前是世界一流的生产绒、肉两用品种。多性状动物模型被认为可以显著提高家畜和家禽遗传评估的准确性，实现性状间的间接选择。本研究利用内蒙古绒山羊早期生长性状的系谱、基因型、环境和表型记录，构建多性状动物模型，然后采用 ABLUP、GBLUP 和 ssGBLUP 三种方法估计早期生长性状（初生重、断奶重、断奶前平均日增重和周岁重）的遗传参数和基因组育种值。进一步采用五重交叉验证法评估基因组估计育种值的准确性和可靠性。结果表明，三种方法估计的初生重遗传力为 0.130.15，断奶重遗传力为 0.130.20，断奶前平均日增重遗传力为 0.110.14，周岁重遗传力为 0.090.14，均属于中低遗传力。断奶重与断奶前平均日增重、断奶前平均日增重与周岁重之间存在较强的正遗传相关，相关系数分别为 0.770.79 和 0.560.67。性状间表型相关也存在相同的模式。ABLUP、GBLUP 和 ssGBLUP 方法估计的初生重的估计育种值的准确性分别为 0.5047、0.6694 和 0.7156；断奶重分别为 0.6207、0.6456 和 0.7254；断奶前平均日增重分别为 0.6110、0.6855 和 0.7357；周岁重分别为 0.6209、0.7155 和 0.7756。综上所述，内蒙古绒山羊早期生长性状属于中低遗传力，遗传改良速度相对较慢。可以通过选择断奶重来实现其他生长性状的遗传改良。ssGBLUP 方法在估计内蒙古绒山羊早期生长性状的基因组育种值方面具有最高的准确性和可靠性，显著高于 ABLUP 方法，表明该方法是内蒙古绒山羊早期生长体重基因组育种的最佳方法。
