Hormones in Males

10.2.2 Hormones in Males Testosterone The testicles produce this hormone. It is responsible for the changes that occur in a male's body at maturity. For example, testosterone causes the following: the penis enlarges, male goats develop an 'odor', oxen develop their 'humps' and their muscles, male animals develop a desire to breed female animals, and sperm begin to mature in the testes. If a male animal is castrated, then the source of testosterone is removed and these changes do not occur.

Reproductive System of a Male Animal (Bull)

Reproductive System of a Female Animal (Cow)