BHOBCFarms
Exploring the pasture
So, I just noticed that one of my ewes, "Betty" is expecting a lamb. I had no idea she was pregnant. Mini Cheviots are fall breeders, so I was a bit confused about how it happened until I read about "The ram effect". Apparently introducing a ram to a ewe that has been isolated from a ram for 6 weeks or more can cause them to ovulate. Live and learn.
"The "ram effect" is when non-cycling (anestrus) ewes are stimulated to ovulate by the sudden introduction of a ram or "teaser" ram. Rams produce a chemical substance called a pheromone, the smell of which stimulates the onset of estrus. When ewes and rams are in constant contact (sight or smell), the pheromones are much less effective at inducing estrus.
Ewes that are not cycling when a ram (or teaser) is introduced will 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. It is expected that 60 to 70 percent of the ewes will conceive at the first normal estrus. Of the remaining ewes, 60 to 70 percent should conceive at the second 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, sound, or smell, which means that they must be separated by distance.
The ram effect is not as effective with ewe lambs, and is most effective during the transitional period when ewes have not begun to cycle, but are almost ready to. Breed of ram can affect ewes' response to the ram effect, with the less-seasonal breeds being more effective at bringing non-cycling ewes into estrus.
The great value of the ram effect is the synchronization of estrus activity which will result in large numbers of ewes ovulating, conceiving, and lambing in a relatively short period of time. To be effective, it is important to have adequate numbers of young, healthy rams. Teaser (vasectomized) rams or testosterone-treated wethers can also stimulate the ram effect." http://www.sheep101.info/201/ramrepro.html
"The "ram effect" is when non-cycling (anestrus) ewes are stimulated to ovulate by the sudden introduction of a ram or "teaser" ram. Rams produce a chemical substance called a pheromone, the smell of which stimulates the onset of estrus. When ewes and rams are in constant contact (sight or smell), the pheromones are much less effective at inducing estrus.
Ewes that are not cycling when a ram (or teaser) is introduced will 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. It is expected that 60 to 70 percent of the ewes will conceive at the first normal estrus. Of the remaining ewes, 60 to 70 percent should conceive at the second 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, sound, or smell, which means that they must be separated by distance.
The ram effect is not as effective with ewe lambs, and is most effective during the transitional period when ewes have not begun to cycle, but are almost ready to. Breed of ram can affect ewes' response to the ram effect, with the less-seasonal breeds being more effective at bringing non-cycling ewes into estrus.
The great value of the ram effect is the synchronization of estrus activity which will result in large numbers of ewes ovulating, conceiving, and lambing in a relatively short period of time. To be effective, it is important to have adequate numbers of young, healthy rams. Teaser (vasectomized) rams or testosterone-treated wethers can also stimulate the ram effect." http://www.sheep101.info/201/ramrepro.html
