Inbreeding values become accessible to sheep breeders

The project, which involves EGENEs (SRUC’s genetic evaluation service) and BASCO, will mean inbreeding values will be available to all registered Suffolk, Texel and Hampshire breeders, and those flocks that performance record through Signet Breeding Services

In trying to improve the genetic makeup of their sheep, breeders are constantly mating the best rams and ewes together. Within any breed, if this approach is taken to an extreme, it will result in animals being mated that have common ancestors – this relatedness can be measured and is expressed as an inbreeding value.

Inbreeding values are published on the BASCO websearch (www.basco.org) and produced for all animals providing they have a full three-generational pedigree (all eight great-grandparents are known).

Values range between 0% and 100%, however high values (very inbred animals) are relatively rare. The mating of half-siblings would result in an inbreeding value for their progeny of 12.5%. Breeders are advised to keep the inbreeding value of individuals below 6%. Animals with high inbreeding values can be used successfully in breeding programmes; they just need to be mated to non-related animals.

New on-line software has recently been developed through BASCO to help breeders determine the level of inbreeding likely to arise in potential matings. This service will be trialled by breeders this autumn.

EBLEX breeding specialist Sam Boon said: “Breeders need to strike a balance to optimise rates of genetic gain, while controlling increases in levels of inbreeding.

“The availability of this information enables breeders to optimise their selection decisions.”