Effect of Induced Hypothyroidism on the Fertility of Male Goats

To study the effect of induced hypothyroidism on fertility status of male Black Bengal goats, 10 adult healthy mature males were divided into control and treated groups. Hypothyroidism was induced successfully by injecting thiourea subcutaneously initially for 15 days at the rate of 100 mg/kg body weight, followed by 66.7 mg/kg body weight for the subse quent 15 days. This resulted in a decrease (p < 0.01) in plasma tri-iodothyronine, thyroxine and testosterone levels, with increasing duration of thiourea treatment. It also adversely affected semen quality, ejaculate volume, sperm concentration, motility and viability. Live percentage declined to 75% for treated and control remained at 90%. Artificial insemination fo female goats with semen of thiourea-treated goats, resulted in failure of conception. However, females inseminated with semen of male goats of control group showed 100% conception. These observations indicate that, thyroid hormones play a key role in maintaining the normal reproductive processes of male goats.