Hormone Responsible for Oviposition in Poultry

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

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.