Stop belief that a sick sheep is a dead sheep
Most sheep farmers lose 1-2pc of lambs from lambing to sale. In the past low lamb prices did little to encourage preventative measures. Price increases have changed circumstances, however.
Most mid-summer deaths can be attributed to clostridial diseases or pasteurellosis. Pasteurellosis can also reduce lamb thrive.
In an extensive trial carried out in the UK in 2003, it was shown that for every sheep in the flock that died there was a further cost, equivalent to another dead sheep, when treatments of ill animals, loss of performance and associated labour were taken into account. I have never vaccinated against clostridial diseases or pasteurella in the past but intend to do so this year, probably giving the first dose in early May when the lambs are being given their first worm treatment.
Lambs are given the first worm dose (against nematodirus) on the basis of the annual forecast, age (around five weeks) and faecal egg counts. Faecal egg counts indicate the presence of egg-laying adults and larvae may have already done damage. In most years the annual forecast (still awaiting this year's forecast) suggests that lambs be dosed early May to mid May.
I normally dose during the first week of May. I take faecal samples from about the third week of April and may well go in earlier should samples contain eggs. I gather further samples from about 14 days from the first dose in order to ascertain if a further dose is required.
Dosing before the infective larvae hatch and are consumed by lambs is a total waste of time and money.
There seems to be some confusion as to the most effective anthelmintic product to use against nematodirus. I normally use a benzimidazole (white) or levamisole (yellow) based product for this dose on the basis that:
1) There is no evidence of anthelmintic resistance to any of the recommended products