Breed Development through Upgrading

Many of the sheep breeds found in the United States are being developed through a technique called upgrading. The United States (like many European countries) has strict regulations on the importation and exportation of live animals and particular breeds. As a result, there are many wonderful sheep breeds that can’t be brought into the United States, like Gotland, Teeswater, Herdwick, Bluefaced Leicester, and Black Welsh Mountain. And yet there are American flocks of all these breeds! 

While we can’t import these sheep, we can import semen. A breeder will choose a breed that is close to the breed they want. For example, if a breeder wants Teeswater, they might choose another longwool breed like Leicester Longwool. A Leicester Longwool ewe is inseminated with semen from a Teeswater sheep. The result is a 50/50 genetic blend. This second-generation sheep is then inseminated with Teeswater semen. The resulting lamb is 75/25 Teeswater.  

This process is continued until the sheep being bred have primarily Teeswater genes. An upgraded flock will never be 100 percent genetically the same as the original breed. American Teeswater may be 95–99 percent Teeswater. But chances are you or I would not be able to tell the difference unless one population or the other were heavily modified. 

At this time, Valais Blacknose – the cutest sheep in the world – are being introduced to the United States via upgrading. 

Upgrading is one way we can help preserve breeds and populations that are rare or threatened. Sometimes there aren’t enough sheep left in a population to have sustainable genetic diversity. Upgrading offers a solution for saving threatened breeds. 

Have you ever spun a fleece from an upgraded sheep? If so, what genetic percentages did it have? What qualities did the fleece have?