Topics:
Animal Refresher, Poultry Science
Hormone Responsible for Oviposition in Poultry
The hormone responsible for oviposition (egg laying/expulsion) in poultry is:
- Growth hormone
- Prolactin
- Vasotocin (AVT) — Correct Answer
- Oxytocin
Explanation:
Correct Answer: Vasotocin (AVT — Arginine Vasotocin)
Arginine Vasotocin (AVT), also called Vasotocin, is a hormone secreted from the posterior pituitary in birds. It causes contraction of the uterus (shell gland), resulting in oviposition — the process of laying the egg.
Vasotocin vs. Oxytocin
- Vasotocin (AVT) is the avian equivalent of Oxytocin in mammals.
- Oxytocin causes uterine contractions and milk let-down in mammals (cows, sheep).
- Vasotocin causes uterine (shell gland) contraction and oviposition in birds.
Complete Reproductive Hormone Summary for Poultry
| Hormone | Source | Function |
|---|---|---|
| FSH | Anterior pituitary | Follicle development |
| LH | Anterior pituitary | Ovulation trigger |
| Prolactin | Anterior pituitary | Broodiness |
| Vasotocin (AVT) | Posterior pituitary | Oviposition (uterine contraction) |
| Oestrogen | Ovary | Secondary sex characters; Ca mobilization |
| Progesterone | Ovary | LH surge; oviduct function |
Why Other Options Are Wrong
- Prolactin → responsible for broodiness, not oviposition.
- Growth hormone → promotes growth; unrelated to oviposition.
- Oxytocin → the mammalian equivalent; in birds, Vasotocin performs this role.
📚 About this Topic — Animal Refresher
This multiple choice question is from Animal Refresher, Poultry Science. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Refresher to strengthen your preparation.
