Vasectomising Rams

Published on: Apr 12, 2019

Recently I was asked to vasectomies two rams for a local farmer. There are many benefits to a sheep farmer for having a vasectomised (teaser) ram.  

These include: 

• Synchronisation of lambing  
• Advancing of lambing Dates 
• Improvement of lambing percentage 
• Ewe hogget selection 
• Identification of dry ewes. 
• Identifying cycling ewes 

 

The procedure involves selecting rams that are healthy but otherwise not suitable to use as breeding animals, perhaps they have a disqualifying feature that means they cannot be registered as a pedigree. Once selected the rams are sedated, this keep them calm and ensure they don’t move during the operation. We infiltrate the scrotal skin with local anesthetic so the rams are not in pain. Each ram also receives a dose of pain relief and an antibiotic injection to prevent secondary infection. After the skin has been clipped and cleaned. A small incision in made through the skin over the spermatic cord. The Vas Deferens is identified and a section is removed, with either end being ligated. This prevents sperm from entering into the urethra and thereby prevents fertilisation. The skin incision is sutured at which point the rams are starting to wake up from their sedation. 

 

Although these teaser rams are now sterile, they are still able to produce the natural pheromones of a fertile Ram. It is these pheromones that we want to utilise to improve the performance of the breeding ewes; this is called the “Ram effect”.  

The Ram effect is a powerful natural phenomenon that utilised the effects of male pheromones on non cycling ewes. These potent pheromones are secreted in the wool wax of both Rams and Teasers. When a female sheep smells these pheromones it produces an immediate hormonal response. Within hours the hormones that are responsible for the oestrus will be increasing in the sheep blood. As a result, almost all the ewes in the flock will ovulate within a few days of introducing the males. The ram effect will only work if the ewes are not exposed to the sight, sound and smell of a ram for a minimum of 21 days prior to teasers being introduced.  

 

Because ewes are normally short day breeders, this means that they only ovulate during the winter. With the addition of a teaser ram, you can stimulate you ewes to start breeding earlier than normal and also synchronise ewes to lamb in a closer group. By allowing a ewe to cycle before she is mated with a fertile Ram, you are increasing her chances of having twins. Ultimately, all these factors means for the farmer it is easier to manage staff around lambing. More lambs will be born and of a similar size, this makes more fitter lambs ready for sale earlier in the season, hopefully reaching a better price. 

 

Vasectomy can also be used for Pet rams as a lower risk alternative to castrating older rams. This is because the blood vessels leading to the testicles are not cut, which reduces the risk of haemorrhage. There is also a much smaller incision with vasectomy, which means there is a lower risk of infection and wound breakdown.

Farm Vet Kate