Short-Day Breeders – Identification

Mare is a long-day breeder, while which of the following is/are short-day breeders?

Correct Answer: All the above (Sheep, Buffalo, Camel)

Short-day breeders are stimulated to breed by decreasing day length (shortening photoperiod — autumn/winter). Sheep, buffalo, and camel are all short-day breeders.

Photoperiod Classification of Seasonal Breeders

• Long-day breeders (increasing daylength stimulates breeding): Mare, Cat
• Short-day breeders (decreasing daylength stimulates breeding): Sheep, Goat, Buffalo, Camel ✔

Mechanism

• Melatonin (secreted by the pineal gland during darkness) is the key mediator.
• Short-day breeders: high melatonin (long nights) → stimulates GnRH → breeding season begins.
• Long-day breeders: low melatonin (short nights) → stimulates GnRH → breeding season begins.

Non-Seasonal (Polyestrous) Animals

Cow, sow, and bitch cycle throughout the year — they are not strictly seasonally controlled by photoperiod.