Sperm abnormalities associated with vitamin A deficiency in rams

During the mating season, sheep in rainfed areas of Iraq graze only on stuble. Vitamin A deficiency during this period may influence semen quality of rams and consequently affect flocks fertility. The effect of vitamin A reduction on types and percentage of abnormal sperms were evaluated. Tweleve mature Awassi rams were randomly assigned to 0 (Control, C), 100,000 IU (T1) and 200,000 IU (T2) for 5 months. The vitamin A content in blood plasma decreased in group C by 77% and increased in group T1 by 57% and in group T2 by 74% between weeks 0 and 20. The abnormal spermatozoa percentages were higher in group C from week 6 onward. The abnormalities of the head of the spermatozoa (giant, small, tapering and pyriform) were higher in group C compared to the vitamin A-treated groups. The lower level of vitamin A in group C resulted in higher abnormality of the midpiece and coiled tail compared to the treated groups. It is concluded that sperm abnormalities increased with the decrease in vitamin A level and treatment with vitamin A decreased these abnormalities. Treatment of rams with vitamin A during the mating season could improve flock fertility.