Artificial insemination has been used recently in chickens to improve fertilization rates in local breeds; however, one of the factors affecting semen quality of chickens is peroxidation lipid in sperm because it contains many long-chain polyunsaturated fatty acids, which cause damage to sperm and reduce fertility in chickens. Therefore, the objective of this study was to find out the best level of vitamin E supplementation and the best time of semen collection as a basis for the improvement and improvement of sperm quality of Noi crossbred cocks. This study was designed completely randomized with 20 Noi crossbred cocks (10-12 months of age, 2037.6 ± 134.6 g of body weight) were fed 5 dietaries of vitamin E (0.75 and 125 mg with/without germinated rice [Gr]) and 2 semen collection times (3 and 7 days) with 10 replicates/9 collection times. Semen samples were stored at 5 oC and sperm quality was analyzed at 0, 4, 6, and 12 hours of time storage. Vitamin E supplementation had no effect on semen weight and semen collection time nor on sperm volume of roosters (P > 0.05). However, E75Gr gave the largest volume of semen (0.34 ml), the highest pH, and the lowest sperm concentration. The time of collection at 7 days had the heaviest semen weight (0.43 g), while in 3 days had the highest pH and lowest sperm concentration. The interaction between vitamin E supplementation and the collection time was statistically significant in terms of semen pH and percentage of sperm abnormality (P < 0.05). There was a significant difference in pH among treatments supplemented with vitamin E at 0 and 4 hours after semen storage (P < 0.05). At 4 hours and 6 hours of storage, the percentage of sperm abnormality had a statistically significant difference among treatments (P < 0.05), E75Gr had the lowest value compared to the peak of E75 (P < 0.05). The research results recommended supplementing with E75Gr diet and collecting semen at 7 days for the best sperm quality.

Keywords: alpha tocopherol, breed rooster, semen characteristics, semen storage