Fertile Life Span of Ova in Bitch

The fertile life span of ovulated ova in domestic animals is 12–24 hours. But in case of the bitch, ova remain fertile in the oviduct for:

Correct Answer: 4–8 days

In the bitch, ovulated ova remain fertile in the oviduct for an exceptionally long period of 4–8 days — compared to 12–24 hours in most other domestic animals.

Why Ova Remain Fertile Longer in the Bitch

• The bitch is unique in that she ovulates primary oocytes (not secondary oocytes like most other species).
• After ovulation, these primary oocytes undergo first meiotic division (→ secondary oocyte) in the oviduct over 2–3 days.
• Only after maturation to secondary oocyte stage can fertilization occur.
• The combination of long maturation time + subsequent fertilization window = 4–8 day fertile lifespan.

Species That Ovulate Primary Oocytes

• Bitch and mare — both ovulate primary oocytes (unique among domestic animals).
• All other domestic animals ovulate secondary oocytes.