Abstract: [Objective] This study aimed to investigate the effects of dietary supplementation with different doses of Angelica extract on production performance,serum antioxidant indicators,and rumen function in dairy cows.[Method] Eighty-four healthy lactating Holstein cows were randomly divided into four groups： the control group （group A） was fed a basal diet,while the treatment groups （groups B,C,and D） were supplemented with 100,300,and 500 mg/kg of Angelica extract,respectively,based on the basal diet. The experiment lasted for 30 days,during which production performance,milk composition,serum antioxidant indicators,and rumen fermentation parameters were measured.[Result] Compared with the control group,supplementation with 300 mg/kg and 500 mg/kg of Angelica extract significantly increased average daily feed intake and milk yield （P<0.05）,reduced the feed-to-milk ratio,and significantly improved milk fat rate and milk protein rate while reducing somatic cell count in milk （P<0.05）.Regarding serum antioxidant indicators,activities of superoxide dismutase （SOD）,catalase （CAT）,and glutathione peroxidase （GSH-Px） were significantly increased,and malondialdehyde （MDA） content was significantly decreased in the treatment groups （P<0.05）. In terms of rumen fermentation,the contents of microbial crude protein （MCP）,acetate,and propionate were significantly increased （P<0.05）,while no significant effects were observed on rumen pH or the contents of butyrate and isobutyrate.[Conclusion] Dietary supplementation with 300~500 mg/kg of Angelica extract can effectively improve production performance,milk quality,antioxidant capacity,and rumen function in dairy cows,demonstrating its potential as a functional feed additive.

Key words: Angelica extract, dairy cows, production performance, antioxidant activity, rumen function