| Endocrine gland | Hormone | Functions | |
| 1. | Placenta | estrogen | initiates secretion of milk |
| 2. | Corpus luteum | estrogen | essential for the maintenance of endometrium |
| 3. | Leydig cells | androgen | initiates the production of sperm |
| 4. | Ovary | FSH | stimulates follicular development and the secretion of estrogens |
Compared to a bull, a bullock is docile because of:
1. higher levels of thyroxin
2. higher levels of cortisone
3. lower levels of blood testosterone
4. lower levels of adrenalin/noradrenalin in its blood