31 March 2000

Feed to beat worms

EWE immunity to worms breaks down before pregnancy, but ensuring adequate protein is fed could help avoid concerns.

Edinburgh-based researcher Jos Houdijk told delegates that controlling the ewes pre-lambing breakdown of worm immunity may help cut dependence on wormers.

"Ewes have a rising nutrient demand during pregnancy and more goes to reproductive effort rather than maintaining the immune system. We wanted to find out if protein or energy was limiting in the diet and so fed pregnant ewes one of three rations – low protein and energy, low protein and high energy or high protein and energy."

The ration was fed for six weeks, with faecal egg counts taken every week. Ewes on the low protein and energy ration had a far higher FEC than the two other groups, which led Dr Houdijk to believe that protein was the limiting factor.

Ewes on the high protein, high energy ration were also found to be heavier and in better condition than those on other diets. Dr Houdijk said changes in protein and energy intake closely reflected changes in backfat and muscle depth and, to a lesser extent, body condition score.

He said basing need for protein supplementation on body condition score alone might not always be effective. But ewes in poor condition – body condition score of 2.5 or less – could benefit from improved protein nutrition to boost their immune response, he added. &#42