Estrous Cycle in Sheep and Goat

The normal estrous cycle length in sheep is 17 days and in goat is 21 days. Photoperiodism is a characteristic of the reproductive cycle or sexual receptivity in sheep and goats.

A reduction in daylight to about 10 or 11 hours, whether it occurs naturally or whether it is induced artificially by penning the ewes in a darkened area during part of the day, will induce the onset of estrous cycle in anestrus ewes.

In both sheep and goats  a considerable variation in the cycle length occurs due to:

• Breed differences
• Stage of breeding season
• Environmental stress

During early breeding season, premature regression of corpus luteum or anovulation results in abnormally short cycles.

Estrus lasts for 24-36 hours in ewe and 24-48 hours in the doe. Duration of estrus is influenced by:

• Both species
• Breed
• Age
• Season
• Presence of male influences

Symptoms of Estrus in Doe

Estrus symptoms are more conspicuous in does and include

• Restless
• Frequent bleating
• Tail wagging from side to side and up and down (most reliable sign)
• Reduced appetite
• Decreased milk production
• Vulva edematous and congested
• Clear mucus discharge from the vagina
• Occasionally does exhibit homosexual behaviour

Symptoms of Estrus in Ewe

Estrus symptoms are relatively inconspicuous, and is not evident in the absence of ram:

• Ewes seek the ram, and together form a following “harem”
• Vulva edematous and congested
• Clear mucous discharge from the vagina
• Waggles her tail and moves it laterally