Seasonal variation in seminal and testicular characteristics of Brazilian Somali rams in the hot semi-arid climate of tropical northeast Brazil.

The seasons in the 1 year study were classified as rainy, transitional rainy-dry, dry, and transitional dry-rainy. Semen pH and the consistency of the testes did not vary between seasons or among rams. All other characteristics of semen and testis varied between rams. Significant seasonal differences were observed for ejaculate volume, mass, % motility, forward motility score and concentration of spermatozoa, and linear testis measurements. The total number of spermatozoa per ejaculate did not vary seasonally. The magnitude of the seasonal effects was not sufficient to prevent the rams being used for breeding throughout the year.