Abstract: This experiment was conducted to study the effects of potassium formate in drinking water on production performance, immune function, and antioxidant capacity of local hybrid chickens. A total of 480 one-day-old healthy hybrid chickens with similar body weight were selected and randomly divided into 4 groups with 6 replicates in each group and 20 chickens in each replicate. The control group was given normal drinking water, and the experimental groups 1,2, and 3 were supplemented with 350,550 and 750 mg / L potassium diformate in drinking water, respectively. The experiment lasted for 54 days. The results showed that : (1) There were no significant differences in average daily feed intake, average daily gain, feed to gain ratio, and immune organ index between the experimental groups and the control group (P>0.05). (2) Adding different doses of potassium formate in drinking water could significantly increase the villus height of the duodenum, jejunum, and ileum of chickens (P<0.05), and groups 1 and 3 could significantly increase the crypt depth of the duodenum of chickens (P<0.05). Compared with the control group, the intestinal villus height/crypt depth (V/C) value of ileum was significantly increased in the experimental group 1, and the V/C value of duodenum and jejunum was significantly increased in the experimental group 2 (P<0.05).Compared with the control group, the serum total protein concentration, immunoglobulin A, and immunoglobulin G were significantly increased in the experimental groups 1 and 2 (P<0.05). The serum albumin concentration, tumor necrosis factor-α concentration, and interleukin-6 were significantly increased in the experimental groups 2 and 3 (P<0.01). (3) Compared with the control group, experimental groups 2 and 3 significantly increased the DPPH free radical scavenging ability of chickens (P<0.05), significantly increased the Superoxide dismutase activity, and inhibited the hydroxyl radical ability of chickens (P<0.01). In conclusion, the addition of potassium formate in drinking water had no effect on the production performance of local hybrid chickens, but it could improve the immune function and antioxidant capacity of chickens, and the effect of adding 550 mg/L was better.

Key words: Chicken; Potassium diformate; Production performance; Immune function; Antioxidant capacity