Baa-baa black sheep flock to vets' aid

A flock of Scottish black-faced sheep is helping scientists at Glasgow University's veterinary school in their battle to beat the scourge of parasites in the animal.

The research team, headed by Mike Stear, has discovered a naturally-occurring gene that makes lambs 50 times more resistant to parasitic worms, which pose major problems to all mammals, including humans.

Sheep farmers in the third world, often among the poorest of the population, are particularly vulnerable, and the parasites eventually develop resistance to the costly drugs used to treat parasitic disease.

The gene works by identifying certain protein molecules in the parasite and then directs the sheep's immune system to inhibit the worm's growth.

The worms in the resistant sheep produce fewer eggs and this also reduces the level of infection among less resistant sheep in the flock.

The Glasgow researchers have also developed highly sophisticated methods of measuring the level of parasite infection in individual sheep, and believe traditional breeding methods linked to high-tech procedures can produce resistant, healthier sheep.

"It is now possible to breed sheep with improved worm resistance and superior productivity in the developed and developing world, using a combination of traditional breeding methods and modern molecular technology," Dr Stear said.

Initial funding for the project came from the Overseas Development Agency, and the team is now seeking support for a five-year commercial breeding trial.