The influence of experimentally induced copper deficiency on the fertility of rams. I. Semen parameters and peripheral plasma androgen concentration.

The influence of molybdenum and molybdenum plus sulphate-induced copper deficiencies on semen quality and peripheral plasma testosterone concentrations in South African Mutton Merino rams was investigated. All animals received an identical ration, supplemented with molybdenum in one group (M) and molybdenum plus sulphate in another (MS) while the control group (C) received additional copper supplementation. After almost a year on these rations, rams in Group MS produced ejaculates of lower volume, lower sperm concentration, poorer sperm motility and morphology than rams of the other 2 groups. The fructose concentration in the ejaculates of group MS rams was also lower than that of rams in the other groups. Peripheral plasma testosterone concentrations in Group MS were lower than in Groups C or M. Liver copper concentrations and clinical signs were consistent with a severe copper deficiency in Group MS and a mild deficiency in Group M. After the copper deficiency was reversed, the above parameters reverted to normal. It was concluded that an experimentally induced copper deficiency produced reversible impairment of testicular function in rams.