固原黄牛遗传背景及其体尺指数、肉用指数分析

Analysis on Genetic Background and Body Size Indexes and Beef-purpose Index of Guyuan Cattle

旨在鉴定固原黄牛是相对独立的肉牛遗传资源,进一步描述其生长发育规律,为固原黄牛肉用种质资源的鉴定和选育提供一定的理论依据。本研究通过历史文献和调查研究分析固原黄牛的演变历史;使用GGP Bovine 100K基因芯片检测和公共数据库中下载包括固原黄牛在内共计13个品种、337个个体全基因组遗传变异数据,通过多维标度分析和构建邻接法系统发育树,分析固原黄牛遗传背景;以红安格斯牛×固原黄牛杂交牛为对照群体,测定与收集不同生长发育阶段固原黄牛的体重、体尺、背膘厚和眼肌面积等表型数据,参照《中国畜禽遗传资源志·牛志》公开发表的秦川牛和蒙古牛的表型数据,从表型描述挖掘固原黄牛相关指标的群体规律。结果表明,固原黄牛是固原本土黄牛与周边蒙古牛和秦川牛相互影响,经过长期选育形成的体型外貌一致的独特类群;现存固原黄牛群体在遗传结构上与邻近的秦川牛和晋南牛遗传关系较近,是相对独立的资源群体;与固原黄牛青年母牛相比较,固原黄牛成年母牛体躯指数提升了9.57%;用红安格斯牛杂交改良后,固原黄牛杂交牛母牛胸围指数和体躯指数分别提升了11.59%、12.70%,固原黄牛杂交牛公牛体长指数、胸围指数分别提升了15.15%、19.26%;固原黄牛成年母牛肉用指数为2.65±0.46,固原黄牛成年公牛肉用指数为2.87±0.35,均属役用牛;固原黄牛公牛背膘厚为(5.29±1.41)mm,高于蒙古牛公牛背膘厚(4.00±1.00)mm;固原黄牛公牛眼肌面积为(62.17±8.51)cm^(2),介于秦川牛公牛眼肌面积(79.80±9.70)cm^(2)和蒙古牛公牛眼肌面积之间(50.40±9.80)cm^(2)。固原黄牛是新的肉牛遗传资源,拥有良好的肉用种质特性,但其体尺指数、肉用指数还未达到专用化肉牛标准,后期需要加强选育,并进行良种扩繁和遗传改良,进一步发挥其种质资源特性。

The purpose of this study was to identify Guyuan cattle as relatively independent beef cattle genetic resources,further describe their growth and development rules,and provide certain theoretical basis for the identification and breeding of germplasm resources for meat of Guyuan cattle.The evolutionary history of Guyuan cattle was analyzed through historical documents and investigation.The whole genome genetic variation data of 337 individuals of 13 breeds including Guyuan cattle were detected through GGP Bovine 100K gene chip and downloaded from public databases,and the genetic background of Guyuan cattle was analyzed by multidimensional scaling analysis and adjacent phylogenetic tree.Taking the Red Angus×Guyuan crossbred cattle as the control population,the phenotypic data such as body weight,body size,backfat thickness and loin eye area of Guyuan cattle at different growth stages were measured and collected,with refe-rence to the phenotypic data of Qinchuan cattle and Mongolian cattle published in the Journal of Chinese Livestock and Poultry Genetic Resources·Cattle,the population rule of relevant indicators of Guyuan cattle was excavated from the phenotypic description.The results showed that:1)Guyuan cattle was a unique population with the same shape and appearance after long-term breeding due to the mutual influence of Guyuan native cattle with neighboring Mongolian cattle and Qinchuan cattle;2)The genetic structure of existing Guyuan cattle population was close to the neighboring Qinchuan cattle and Jinnan cattle,and it was a relatively independent resource population.3)Compared with heifer of Guyuan cattle,somatic index of adult cow of Guyuan cattle was increased by 9.57%;4)After crossbreeding with Red Angus cattle,brassiere index and somatic index of adult cow of crossbred Guyuan cattle were respectively increased by 11.59%and 12.70%,body length index and brassiere index of bull of crossbred Guyuan cattle were respectively increased by 15.15%and 19.26%;5)Beef-purpose index of adult cow of Guyuan cattle was 2.65±0.46,beef-purpose index of bull of Guyuan cattle was 2.87±0.35,and Guyuan cattle was draft cattle;6)The backfat thickness of bull of Guyuan cattle was(5.29±1.41)mm,higher than the backfat thickness of bull of Mongolian cattle(4.00±1.00)mm;7)The loin eye area of bull of Guyuan cattle was(62.17±8.51)cm^(2),between the loin eye area of of Qinchuan cattle(79.80±9.70)cm^(2) and Mongolian cattle(50.40±9.80)cm^(2).Guyuan cattle is a new genetic resource of beef cattle,which has good germplasm characteristics for meat.However,its body size indexes and beef-purpose index have not reached the standard of specialized beef cattle.In the later stage,strengthen breeding and the stock breeding and genetic improvement of Guyuan cattle are needed to further develop its germplasm resource characteristics.