Attività circannuale delle gonadi nell'ariete di razza Sarda

Seasonal gonadal activity in rams from Sardinia. All over a year in eight rams the testicular diameter and the plasma testosterone level were determined. The least testicular diameter was found out in march, then it increased with peak in august. After that month the testicular diameter regressed a little in september-november, dramatically in december and again a little till march. The plasma level changes of testosterone appeared to be correlated with the testicular diameter but it increased to a maximum in july. A possible interrelationship between the light and the seasonal cycle is discussed.