Genetic gains help cut sheep worm resistance [from FWi]
05 August 2010
Having selected sheep for parasite resistance, Richard Chantler has reduced anthelmintic use by half, according to an article on Farmers Weekly Interactive.
One of the UK's leading New Zealand Romney breeders is making significant progress towards worm resistance in his flock, and claims that breeders may soon be in a position to sell certificated sheep with a given level of resistance.
Richard Chantler says research scientists in New Zealand are close to identifying the genes for worm resistance. "I believe it won't be long before we will be able to sell certificated sheep with a given level of resistance, be that single copy or double,'' says Mr Chantler who, with his wife, Penny, runs a flock of 300 pure-bred New Zealand Romneys at Hill Farm, Llanigon, Hay-on-Wye.
Worm resistance has been a priority as the Chantlers have developed their flock, using semen from Murray Rohloff's Awereka stud in the South Island. For the past 15 years this New Zealander has been breeding for worm resistance. Mr Chantler selects sheep for their parasite resistance, using the Fecpak on-farm faecal egg count kit. By collecting sheep droppings, he has successfully reduced by half the reliance on anthelmintics for internal parasites. This year, the average worm count a sheep has dropped from about 800 eggs/g of faeces to 200 eggs/g.
"We believe drenching sheep is an unnecessary chore," he says. "Drench resistance is too common around the world; drugs are becoming unpopular and it is harder to find new ones."