New mannequin reveals blowfly strike may price farmers £209/lamb

Mortalities because of blowfly strike may very well be costing farmers £209/lamb and £184/breeding ewe, in line with an up to date blowfly costing mannequin.

The up to date mannequin now displays the latest modifications in farm economics, new data of insecticidal merchandise and the influence of a altering local weather.

Developed by the College of Bristol, the mannequin reveals that the estimated lack of £209/lamb relies on the earnings misplaced from not promoting the animal and the common price of rearing a substitute lamb.

The lack of £184/breeding ewe relies on the price of rearing a substitute ewe lamb and the worth of a cull ewe.

Ruminant technical guide at Elanco Animal Well being, Matt Colston, stated the brand new figures spotlight the monetary penalties of blowfly strike and why preventative therapy is paramount.

Colston stated the mannequin seems at totally different administration methods – starting from no therapy in any respect, to a mix of various remedies with preventative Insect Progress Regulator (IGR) merchandise and pyrethroid merchandise – in low, medium and high-risk eventualities for strike.

“In all instances, preventative therapy for ewes and lambs is probably the most cost-effective technique, and never treating sheep to stop strike is prone to be the most expensive technique,” he stated.

Monetary implications

The mannequin relies on a lowland 250-ewe breeding flock rearing a mean of 1.5 lambs/ewe and predicts that 22 ewes and 36 lambs might be struck by flystrike in a medium-risk situation.

The monetary implications of this, based mostly on a 5 p.c mortality fee, are an estimated price to the farmer of £1,834, and this will increase to £3,483 in a high-strike danger situation.

Colston highlighted that, though the earlier mannequin urged that no therapy was an economical possibility for low-risk flocks, that is now not the case.

“Counting on the identification of struck animals after which administering therapy is now not cost-effective,” he stated.

“This is because of a rise within the incidence of flystrike, alongside the upper market worth of lambs compared to the price of therapy.

“Loads of farmers don’t realise that in the event that they don’t put their preventative therapy on early within the season, extra flies can have reproduced, leading to greater populations by center of the summer time.

“By that time, the problem could be very overwhelming and as this up to date costing mannequin reveals, the monetary penalties could be extreme.”