For those in the know, teaser rams provide an invaluable and relatively low cost aid in the breeding management of their flock. Dan describes what they are, why they are effective and how to pick the best ones.

What are teaser rams?

Teasers are entire males that have undergone a vasectomy. As in other species this entails having the vas deferens (the tube that carries the sperm from the testicles to the penis) cut with each end being permanently (hopefully!) tied off. As the testicles remain, vasectomised males continue to produce and be influenced by testosterone. They therefore retain all the behavioural characteristics of an entire male.

How can teaser rams be useful?

Teasers can be used to advance the breeding season by around two weeks. But their greatest benefit is frequently said to be in their ability to condense the breeding period and therefore lambing. The majority of ewes will be served in the first fertile cycle after teaser removal with much of the remainder in the second cycle. The long, drawn out tail to lambing can then be reduced. You can then tailor your management and labour requirements to this more intensive period. Teasers are also used ahead of AI programmes to increase conception rates.

Can you choose a teaser from your own flock?

The choice of teaser is critical if you are to get maximal benefit from them
and they are to last. The ram should be fit and healthy. Good legs and feet (to allow him to mount and stay sound) and good eyes and teeth. He is actually going to work harder than the breeding rams so he really does need to be up to the job. To this end he still needs to pass the first stages of the ram MOT.

He should also be of the same health status as the rest of your flock. This is especially important when buying-in a ‘ready made’ teaser, when quarantine measures and treatments should also be used. This is a good reason for ‘growing your own’ teasers. You can pick a good ram that may not have made the grade for breeding.

Teaser Rams

Lambs can be vasectomised as soon as their bits are big enough, theoretically from about three months of age. But in reality they are better done from around 8-9 months. Although teasers can be used when they are ram lambs they are usually better developed, with a higher libido, as shearlings. With enough planning the next generation of your teasers can be maintained with the procedure performed as ram lambs with them working from shearlings.

How to best use teaser rams?

The breeding season of the ram is important to make sure they are ready and keen to work in the autumn. Early breeders, such as Dorsets and Suffolks are ideal. Though any breed can be used, as long as their natural breeding season is taken into account. To get the greatest benefit from your teasers, ewes should be well away from sight, sound and smell of any ram for at least a month before the teasers go in. This includes neighbours’ rams and last year’s ram lambs. A distance of a mile is usually sufficient to ensure the effect of the teasers is enough to bring ewes into heat when they are introduced.

Various protocols are described but the easiest is to put the teasers in for 14 days and then swap them for the fertile rams. Teasers can work at a ratio of 1 to 50-100 ewes. But it is important to remember that the breeding rams will effectively be working with a group of synchronised ewes and so a ratio of 1 to 20-30 is needed. Ewes will have an initial, silent heat after 3-4 days followed by two peaks of oestrus activity in the ewes 18 and 26 days
later.

The procedure is done on farm, under sedation and usually takes around 30- 35 minutes. A well put together teaser ram should last at least three seasons. If you have any questions or would like to hear the experiences of those using teasers please get in touch with the vets at the practice.