Abstract
Semen preservation by cooling or freezing is an essential artificial insemination (AI) step. AI is affected by many factors, such as semen quality. The aim of this study was to evaluate the effect of adding different concentrations of different antioxidants such as selenium, zinc oxide and Vitamin C to the diluted buck semen during cooling in both summer and winter. Eight mature healthy Zaraibi bucks were used in the study. semen was collected twice weekly during summer 2021 (august and September) and winter 2022 (January and February). Semen samples were collected by an electro- ejaculator device. Samples of good quality semen were pooled and diluted by extender and divided according to experimental groups: Group 1 Vitamin C: 50 mg /100 ml, 1oo mg /100 ml, 150 mg /100 ml. Group 2 Zinc oxide: 0.5 mg /100 ml, 1 mg /100 ml, 1.5 mg /100 ml. Group 3 Selenium: 100 μL/100 ml, 200 μL / 100, 300 μL / 100. After cooling by 1 hr. semen parameters were examined as motility, livability, acrosome integrity and cell membrane integrity and at 8 hours from cooling then every 8 hr till 64 hr. Seminal antioxidant activities as SOD and catalase were estimated at 0 hr, 24 hr and 48 hr. The results indicated that selenium 200 μL / 100 ml diluent has a favorable effect on cooled diluted buck semen during summer and winter more than selenium 100 μL and 300 μL. Selenium is better than Zinc oxide and Vitamin C for improving the semen quality as with minimum cost. In conclusion adding selenium as antioxidant to buck semen during cooling preservation with 200 μL concentration per 100 diluents is preferred for buck semen during cooling preservation.

Key words: Zarabi Buck, Semen preservation, AI, Antioxidant, Selenium, Zinc Oxide, Vitamin C, SOD, CAT, MDA, Biochemical indices