25 April 1997

Stick to worm plan

CATTLE producers should stick to their planned worming programme despite current dry weather in some parts of the country.

So says Scottish Agricultural College vet Mark Crawshaw. "In a normal season, larvae will develop over the three weeks after turnout. But if it is very dry and then becomes wet, all the larvae will develop together, presenting a great challenge. And it may be difficult to treat cattle quickly enough to be effective."

That means producers should stick with the programme they and their vet have agreed upon, he says. "Do not try to cut costs. The cost of worming per head is not high."

Cattle in their first season at grass without their mothers are under greatest threat, he says. "Suckled calves will have a low level of intake, enough to develop some natural immunity. Those most at risk are cattle out for their first grazing season, they must be the priority for control."

Mr Crawshaw also warns against relying on faecal egg counts as a means of deciding whether to worm. "Egg counts give a rough and ready estimate of the risk, you could be lulled into a false sense of security."