Abstract
Background:
This study aimed to examine the effect of vitamin E injection and seasonal changes on semen characteristics (pH, ejaculation volume, mass motility, progressive motility, sperm concentration, live sperm, dead sperm, and abnormal sperm) in rams.

Aim:
This study aimed to evaluate the effectiveness of vitamin E injections in improving semen characteristics in rams.

Methods:
Twenty-one healthy rams were randomly divided into three groups (7 animals for each group) as follows: (1) control group injected with saline solution, (2) rams injected with 2 ml of vitamin E, and (3) rams injected with 4 ml of vitamin E. All doses were injected intramuscularly every 2 weeks during the cold season from December to the end of February 2022 and the hot season from June to the end of August 2023.

Results:
The results showed significant (p < 0.05) differences between the treated groups in most of the semen characteristics. In summer, all of the semen characteristics were significantly increased (p < 0.05), except for the count of dead and abnormal sperm, compared with those in winter. Rams treated with 4 ml of E vitamin caused a significant increase (p < 0.05) in all semen characteristics, while this dose significantly decreased (p < 0.05) the percentage of dead and abnormal sperm in comparison with the control.

Conclusion:
The study suggests that treating rams with 4 ml of vitamin E during the hot season could improve semen characteristics such as pH, ejaculation volume, mass motility, progressive motility, sperm concentrations, and live sperm.

Key words: Vitamin E; Seasonal; Semen characteristics; Rams.