Zinc levels in seminal plasma and blood serum of pubescent nelore cattle, in relation with sperm characteristics and reproductive development

Abstract

The levels of zinc and of acid and alkaline phosphatase in seminal plasma in relation to reproductive development in thirteen Nellore males from ten months of age until puberty, raised on Brachiaria brizantha pasture and receaving mineral salt ad libitum were determined. The reproductive development was determined through scrotal circumference, physical semen characteristics and blood testosterone concentration. The zinc concentrations showed a high individual variation (CV = 64%) with values between 0.3 and 18.3 meg/ml. The animals who reached sooner the puberty had a higher zinc concentration (P < 0.001). A correlation between zinc and blood testosterone level (P < 0.001) was observed. The phosphatase levels were correlated with vigour, motility and sperm defects (P < 0.001).