To investigate the effects of Astragalus polysaccharides on production performance, antioxidant capacity and immune function of dairy cows, and to provide theoretical basis for improving dairy cattle breeding efficiency and health management.

Seventy-two cows with similar first litter, milk production and body condition were selected and randomly divided into four groups: control group (CON), low-dose group (APS 1.5), medium-dose group (APS 3.0) and high-dose group (APS 4.5).The control group was fed the basal diet, and the other three groups were fed the basal diet supplemented with 1.5, 3.0, and 4.5 g/kg Astragalus polysaccharide, respectively.The pre-experimental period lasted 15 d, and the formal experimental period lasted 60 d.during which milk production, milk composition, antioxidant indicators and immune indicators were monitored and analyzed.

Milk production in the APS 3.0 group was significantly improved, milk protein rate, milk fat rate and dry matter content were improved, and somatic cell number was significantly reduced; serum total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities were significantly increased, and malondialdehyde (MDA) content was significantly reduced in each experiment group; The immunoglobulin IgA and IgM contents in the astragalus polysaccharide-supplemented groups were significantly increased, while the tumor necrosis factor-α (TNF-α) content was significantly decreased, with the medium-dose group showing the optimal effect.

Astragalus polysaccharide cansignificantly improve the production performance of dairy cows, enhance antioxidant capacity and immune function, among which 3.0 g/kg addition has the best effect and has high application value in breeding.