Breeding

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Cycle

The majority of sheep breed in the fall and winter - the shorter the days, the higher conception rates. During the peak of summer many ewes do not have an estrus cycle at all and the heat may cause rams to be less fertile.

Ewe lambs are typically 6 months when they have their first heat cycle. The normal cycle for ewes is every 17 days (can vary from 14 to 19 days) with a standing heat (when the ewe can conceive) lasting approximately 30-35 hours.

Pre-Breeding

Prior to breeding, animals should be evaluated for their need for deworming. They should have their hooves trimmed, if necessary.

The Ram Effect

The "ram effect" is when non-cycling ewes are stimulated to ovulate by the sudden introduction of an intact male or "teaser" (vasectomized) ram. Ram pheromones can stimulate the onset of estrus, however, when ewes and rams are in constant contact (sight or smell), the pheromones are much less effective at inducing estrus. Although recommendations vary, rams should be isolated from ewes for at least 6 weeks in order for the ram effect to work. Ewes must have no contact with rams by either sight or smell, which means that they must be separated by distance.

Ewes that are not cycling when a ram (or teaser) is introduced will generally ovulate in 3 to 4 days. This first ovulation will be a "silent" heat, which cannot be detected by the ram. Following this silent heat, there will be two normal estrus peaks, with some ewes cycling around day 18 and the remainder around day 25. Ewes that do not conceive at either of these times may return to heat in another 17 days.

Hormonal control

Hormones can be used to induce and/or synchronize estrus in ewes.

We use CIDR™ (controlled internal drug release) devices and sometimes PG600.

Protocol:

Recommended Supplier: Ryan Thurston, 301-302-3603, RyThurston@aol.com, or message on Facebook.

Gestation

Gestation (the time period from conception to delivery of the lambs) will vary slightly by breed, by ewe and by the number of lambs a ewe is carrying, but typically will be approximately 148 days.

REMEMBER STRESS DECREASES FERTILITY and SURVIVABILITY. During the six weeks before mating, five weeks after conceiving, and four weeks prior to parturition, avoid transport, rough handling, and abrupt changes in diet or location. Hauling the day of the breeding is the only acceptable transportation time.