VGO 511: Veterinary Andrology and Reproductive Techniques (1+1)

INCIDENCE, PATHOGENESIS AND ETIOLOGY

• Testicular hypoplasia may be partial or total due to a failure of germinal cells to develop in the yolk sac, failure to migrate to the gonad, failure to multiply in the gonad or extensive degeneration of early germinal cells after they have entered the gonad.
• Testicular hypoplasia is congenital hereditary in origin is caused by a marked lack of or reduction in spermatogonia in the gonads during fetal life.
• It is observed as a unilateral or bilateral condition at the time of the puberty or later in all of our domestic animals.
• Most commonly seen in bulls, rams, boars and stallions.

Swedish Highland breed with white coat colour is commonly affected. Cattle with black ears were not affected

• In these cattle hypoplasia of left testis occurred about 25 per cent of all bulls, in the right testis 1 per cent and in both testes 4-5 per cent.
• This condition in cattle is due to a single autosomal recessive gene with incomplete penetrance.