Sheep reveal infection clues

SCIENTISTS may have discovered why some people are more prone to infections than others.

Researchers from Edinburgh University and Princeton University in the United States studied sheep populations on the remote Scottish island of Hirta.

They found that sheep with higher levels of antibodies to fend off infection lived longer but gave birth to fewer lambs each year.

Sheep with lower levels of antibodies died younger but gave birth to more lambs.

The study, led by Princeton ecologist Andrea Graham, found that both sets of animals had the same amount of lambs over their lifespan and concluded that the reproductive system compensates for weaknesses in the immune system by producing more offspring in a shorter period of time.