A genetic blueprint of sheep shows how they parted company with goats on the path of evolution around four million years ago.

The sheep genome could also aid the development of DNA testing to speed up selective breeding programmes for farmers.

Scientists identified genes for the sheep fleece and uncovered distinct features of the animals’ digestive system that allowed them to live on a diet of low-quality grass and other plants.

The International Sheep Genomics Consortium compared sheep genes with those of other animals, including humans, cows, goats and pigs.

Several genes associated with wool production were found, as well as others underpinning the evolution of the rumen – a specialised stomach chamber designed to break down tough plant material.

A total of 26 institutions from eight countries took part in the research, published in the latest edition of the journal Science.

Professor Alan Archibald, a member of the team and head of genetics and genomics at the University of Edinburgh’s Roslin Institute, said: “Sheep were one of the first animals to be domesticated for farming and are still an important part of the global agricultural economy.

“Understanding more about their genetic make-up will help us to breed healthier and more productive flocks.”