Effect of Dietary Gossypol on Gonadal and Extragonadal Sperm Reserves of Yankasa Rams

摘要

Cottonseed and its by-products are used extensively for supplementing ruminant rations to increase productivity. However, they contain gossypol which is a reproductive toxicant in males of both ruminant and non-ruminants. This study evaluated the effect of dietary gossypol from whole cottonseed (WCS) and cottonseed cake (CSC) on the gonadal and extragonadal sperm reserves of Yankasa rams. Fifteen (15) Yankasa rams weighing an average of 20 ± 2 Kg were randomly distributed into three groups (A, B and C) of five rams each and were fed diets containing 48 % WCS, 48 % CSC and control diet (gossypol-free), respectively for 14 weeks. The gonadal and epididymal sperm of the rams (3 from each group) were conducted. The data obtained were statistically analysed using GraphPad Prism version 5.0. Significance of differences between treatments means were determined at P ≤ 0.05 with Tukey-Kramer multiple comparison test of repeated measure analysis of variance (ANOVA). Testicular and epididymal weight, length and sperm reserves were not significantly (P > 0.05) affected by gossypol. Gossypol-treated rams in groups A and B however, had numerically lower mean values of testicular and epididymal weight, length and sperm reserves than those of the control group. We concluded that gossypol present in whole cottonseed cottonseed cake which causes reduction in testicular and epididymal sperm reserves and these feeds should be used with caution in breeding rams.