[目的]为奶牛体型缺陷性状线性评估的推广与应用提供数据支撑,以期提高规模化奶牛场遗传改良效果,提升牧场生产水平。[方法]通过对新疆南疆地区3 个规模化牧场2019年和2022年的奶牛体型线性评估结果,结合DHI测定结果,进行奶牛体型缺陷性状线性评估分析。[结果]根据2019年缺陷性线性遗传评估结果,通过遗传改良手段进行针对性改良后,2022年3 个牧场主要缺陷性状比例大幅度下降,平均日单产较2019年提升5.8 kg（P<0.01）,平均体细胞数较2020年下降23.7 万个/mL（P<0.01）,平均乳脂率和乳蛋白无显著差异（P>0.05）。[结论]应用奶牛体型缺陷性线性评估方法,对规模化奶牛场遗传改良具有重要的指导意义,可有效提高牧场牛群生产性能,快速改善群体遗传水平。

[Objective]This study provided data support for the promotion and application of linear evaluation of body size defect traits of dairy cows,in order to improve the genetic improvement effect of large-scale dairy farms and improve the production level of pasture. [Method]Based on the linear evaluation results of body size of dairy cows from three large-scale pastures in southern Xinjiang in 2019 and 2022,combined with the determination results of DHI,linear evaluation analysis of body size defect traits of dairy cows was conducted. [Result]According to the results of linear genetic assessment of defects in 2019,after targeted improvement through genetic improvement,the proportion of main defect traits in the three pastures in 2022 decreased significantly,and the average daily yield per unit area increased by 5.8 kg compared with that in 2019（P<0.01）.Compared with 2020,the average somatic cell count decreased by 237 000 per mL（P<0.01）,the average milk fat percentage and milk protein had no significant difference （P> 0.05）,but milk protein was significantly improved. [Conclusion]The application of linear evaluation method for the size defect of dairy cows has important guiding significance for the genetic improvement of large-scale dairy farms,which can effectively improve the production performance of pasture cows and rapidly improve the population genetic level.