Use of a teaser ram prior to introducing the ram can bring the breeding season forward by up to 2 weeks and increases the number of ewes cycling when the fertile ram is introduced.
Using a teaser (a vasectomised) ram is an effective way to influence the natural breeding cycle of sheep. It can be used to tighten the lambing period, encourage ewes to come into season a couple of weeks earlier than the natural breeding season and stimulate maiden ewes to cycle naturally prior to tupping.
Vasectomy surgery is a relatively simple surgery, performed under sedation, either on farm or at the surgery. A fit, healthy shearling or young ram with good libido should be chosen. It must be performed at least 6 weeks before you are planning to work your teaser so that he is not still fertile. On very rare occasions, teasers can become fertile again; to ensure this hasn’t happened the teaser ram can be semen tested before each mating season.
For effective use, your ewes must have no contact with any rams for 28 days prior to introducing the teaser ram. The teaser(s) can then be introduced 14 days before the tupping date at a teaser to ewe ratio of 1:100. Remove the teaser at your tupping date and then after 24 hours, introduce fertile rams at a ram to ewe ratio of 1:20.