22 March 2002

Wormer confusion

A SURVEY of 1117 farms by an animal health company reveals widespread confusion over how many times/season sheep should be wormed and wormer types.

Conducted by Novartis, the survey showed 32% of producers questioned were worming lambs five or more times, according to Lynda Maris of the company. "Lambs are usually treated 3-4 times depending on how long they are grazing.

"Making better use of clean grazing will help reduce anthelmintic use. Although we sell anthelmintics, it is in our interest to ensure they are used to best effect, otherwise they will lose efficacy more quickly."

Recent reported resistance problems have also highlighted the need to rotate wormers on an annual basis. Yet 64% of flockmasters surveyed were unable to name which of the three wormer groups: benzimidazole, levamisole and avermectin, various active ingredients belonged to, according to Mrs Maris.

"All manufacturers are required to include wormer groups on packs, although they can sometimes be difficult to see." Benzimidazoles are labelled 1-BZ, levamisoles, 2-LM and avermectins, 3-AV, she explains.

Although most producers found difficulty identifying wormer groups, 65% were concerned about wormer resistance. Of respondents, 9% reported having wormer resistance diagnosed in their flocks. &#42