WITH the new lambing season under way, shock evidence has emerged that a killer disease is rife among sheep flocks.

The disease is coccidiosis which can increase lamb mortality by up to 10 per cent, reduce growth rate by 38 per cent and adversely affect feed conversion efficiency, making it more costly to finish lambs for market.

The evidence comes in results of an extensive study carried out by Janssen Animal Health in conjunction with the National Sheep Association.

Nick Burford, of Janssen, said: "In a typical 300-ewe flock, the losses can add up to £1,500 or more, based on a five per cent mortality."

The way to prevent heavy losses, he said, was to pre-treat lambs with an effective anticoccidial at four to six weeks of age, before clinical signs of the disease were evident.