Maternal Recognition of Pregnancy in Sow
Maternal recognition of pregnancy (MRP) in sow is due to:
- Luteal progesterone
- Embryonic estrogen — Correct Answer
- Placental lactogens
- Interferon-tau
Correct Answer: Embryonic estrogen
In the sow (pig), Maternal Recognition of Pregnancy (MRP) is mediated by estrogen produced by the embryo/conceptus around 11–12 days of pregnancy. This embryonic estrogen prevents luteolysis (regression of the corpus luteum) by redirecting PGF2α secretion from endocrine (into bloodstream → C.L. regression) to exocrine (into uterine lumen → local, no C.L. regression).
MRP by Species Summary
- Cattle: Bovine Interferon-tau (bIFN-τ / bTP-1) — at 16–17 days
- Sheep: Ovine Interferon-tau (oIFN-τ / oTP-1) — at 12–14 days
- Pig: Embryonic estrogen — at 11–12 days ✔
- Mare: Transuterine migration of conceptus — at 12–14 days
- Human: hCG (human Chorionic Gonadotropin) — at 8–10 days
- Bitch & Cat: MRP not required (C.L. lasts full gestation regardless)
📚 About this Topic — Animal Refresher
This multiple choice question is from Animal Refresher, Animal Reproduction. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Refresher to strengthen your preparation.