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 vitaminAreduction 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. © 2004 Elsevier B.V. All rights reserved