Abstract: [Objective] This study aimed to investigate the effects of different doses of herbal feed additives on lactation performance,milk quality,serum biochemical indices,and immune function in late lactating dairy cows. [Method] A total of 60 late lactating Holstein cows with similar body weight,parity,lactation period, and milk yield were selected and randomly divided into 4 groups：Control group,Experiment I Experiment II and Experiment III,with 15 cows per group. The control group was fed conventional feed,while Experiment I,II and III groups were supplemented with 100 g/d,200 g/d,and 300 g/d herbal additives,respectively,on the basis of conventional feed. The entire experimental period lasted for 9 weeks. [Result] From the second week,the milk yield in the experimental groups significantly increased （p<0.05）. The milk quality indicators （milk fat rate,lactose rate, and milk protein rate）, serum biochemical indicators （albumin and globulin）,and immune indicators （IgM, IgG, and IL-2） in Experiment II and III groups were significantly higher than those in the control group （p<0.05）. [Conclusion] Herbal feed additives significantly improved the milk yield and milk composition of late lactating dairy cows,enhanced metabolic levels,and boosted immune function,with the optimal effect at 200 g/d. These findings provide a reference for improving dairy cow production efficiency.

Key words: Chinese herbal feed additives, cow, production performance, serum biochemistry, immune