Abstract: [Objective] To study the effects of dietary extract of dysentery on serum antioxidant indexes and intestinal tissue morphology of aborted cows induced by neosporidiosis. [Method] A total of 168 aborted cows with similar age, parity and average milk yield in a large-scale farm were selected as the study objects, and the cows were divided into 4 groups using a single factor randomized trial design. They were divided into control group (basic diet), observation group I (basic diet +200 g/t dysentery extract), observation group II (basic diet +400 g/t dysentery extract) and observation group III (basic diet +600 g/t dysentery extract). Each group was set with 6 replicates and 7 heads per replicate. The pre-test lasted for 7 days and the formal test lasted for 35 days. The changes of serum antioxidant indexes and intestinal tissue morphology of cows in each group were analyzed after the experiment. [Result] Compared with the control group, T-AOC, T-SOD and GSH-Px in observation group I, observation group II and observation group III were significantly increased （P<0.05）, and the highest values were found in observation group II, while there was no difference between observation group I and observation group III （P>0.05）. MDA in control group was higher than that in other experimental groups, and observation group I was higher than that in observation group II and observation group III（P<0.05）. There was no difference in CAT among all groups （P>0.05）. The number of Escherichia coli and Salmonella in control group was higher than that in observation group I, observation Group II and observation group III, and the number of lactic acid bacteria was lower than that in experimental groups （P<0.05）, and the number of Escherichia coli and Salmonella in observation group II and observation group III was lower than that in observation group I, and the number of lactic acid bacteria was higher than that in observation group I（P<0.05）. [Conclusion] Incorporating dysentery extract into the basic diet of cows that have aborted due to neosporidiosis has been shown to enhance their immune function, improve antioxidant capacity, and help maintain intestinal homeostasis. Based on the experimental findings, economic considerations, and other relevant factors, it is advisable to include dysentery extract in the diet at a rate of 400 g/t.

Key words: dysentery extract, neosporidiosis, aborted cow, serum antioxidant index, intestinal tissue morphology