[目的]探究饲料中添加蛋氨酸二肽对奶牛产奶量、乳成分及乳蛋白产量的影响,为蛋氨酸二肽在奶牛养殖中的应用提供试验依据。[方法]选取120 头健康的中国荷斯坦母牛为试验动物,随机分为对照组和试验组,每组60 头,设5 个重复。对照组饲喂常规基础日粮,试验组在基础日粮中额外添加50.0 mg/kg蛋氨酸二肽,试验周期70 d。试验期间测定两组奶牛产奶量、料奶比、体细胞数、乳蛋白等指标。[结果]试验组奶牛料奶比显著低于对照组（P<0.05）,平均日产奶量、高峰奶量极显著高于对照组（P<0.01）;试验组乳蛋白率较对照组提高30.77%（P<0.01）,体细胞数减少75.79%（P<0.01）;试验组牛乳中β-乳球蛋白含量显著提高（P<0.05）,α-酪蛋白、β-酪蛋白、乳铁蛋白和免疫球蛋白含量极显著提高（P<0.01）,κ-酪蛋白含量极显著低于对照组（P<0.01）;两组牛乳中尿素氮、乳糖、乳干物质、乳脂肪含量无显著差异（P>0.05）。[结论]在奶牛基础日粮中添加50.0 mg/kg蛋氨酸二肽,可显著提升奶牛产奶性能,改善乳品质,提高乳蛋白相关指标含量,降低牛乳体细胞数量,对奶牛健康养殖具有积极作用。

[Objective] This study aimed to investigate the effects of dietary supplementation with methionine dipeptide on milk yield, milk composition, and milk protein production in dairy cows, providing experimental evidence for the application of methionine dipeptide in dairy farming. [Method] A total of 120 healthy Chinese Holstein cows were selected as experimental animals and randomly divided into a control group and a treatment group, with 60 cows per group and 5 replicates per group. The control group was fed a conventional basal diet, while the treatment group received the basal diet supplemented with 50.0 mg/kg of methionine dipeptide. The experimental period lasted 70 days. During the experiment, milk yield, feed-to-milk ratio, somatic cell count, and milk protein content were measured for both groups. [Result] The treatment group showed a significantly lower feed-to-milk ratio compared to the control group （P<0.05）, and the average daily milk yield and peak milk yield were highly significantly higher than those of the control group （P<0.01）. The milk protein percentage in the treatment group was increased by 30.77% compared to the control group （P<0.01）, while somatic cell count was reduced by 75.79% （P<0.01）. The content of β-lactoglobulin in milk was significantly increased（P<0.05）,and the contents of α-casein, β-casein, lactoferrin, and immunoglobulin were highly significantly increased （P<0.01）. The κ-casein content was highly significantly lower than that of the control group （P<0.01）. No significant differences were observed between the two groups in milk urea nitrogen, lactose, milk solids, or milk fat content （P>0.05）. [Conclusion] Supplementation of the basal diet with 50.0 mg/kg of methionine dipeptide can significantly enhance the lactation performance of dairy cows, improve milk quality, increase milk protein-related indicators, and reduce somatic cell count in milk, thereby exerting a positive effect on the healthy management of dairy cows.