The effect of cotton defoliant on the abortion rate and reproductive performance recovery in sheep

This study aimed to investigate the impact of cotton defoliant on the abortion rate of pregnant sheep and explore whether progesterone injections could alleviate this damage to provide protective measures for sheep reproductive performance. Based on different application methods of cotton defoliant in cotton stubble fields, the sheep was divided into three groups: drone application field group, manual application field group, and control group without defoliant application in cotton stubble fields. From 2020 to 2022, data of lambing, conception rate and abortion rate were recorded annually in each group. In the experiment on the recovery of reproductive performance in ewes treated with progesterone, breeding ewes from the drone application field group and manual application field group were intramuscularly administered with progesterone reagent of 2 mL with a concentration of 10 mg/mL per injection, at 75, 90, and 105 d of pregnancy after mating, the control group was treated without progesterone injection. The results showed that compared with the control group, the abortion rate of ewes in the two experimental groups using cotton defoliating agent increased, and the abortion rate of ewes in the drone application group was higher than that in the the manual application group.Intramuscular injection of progesterone in ewes at 75, 90, and 105 d of pregnancy effectively reduced the abortion rate, with the lowest rate observed in the group treated with progesterone injection at 90 days of pregnancy. In conclusion, cotton defoliant increased the abortion rate in ewes, causing damage to their reproductive performance and reducing production efficiency. Application of progesterone administration at 90 d of pregnancy proved to be an effective way of recovering sheep reproductive performance damaged by cotton defoliant.