The latest SCOPS forecast shows widespread blowfly risk across the UK, prompting warnings that sheep farmers may need to act earlier than usual this season to help prevent strike.
The forecast, which indicates when blowflies are expected to emerge from overwintered pupae, is now predominantly red.
This indicates flies are emerging, or have already emerged, across most regions, including parts of Scotland where blowfly strike risk would not usually be expected so early in the season.
Carolyn Hogan, ruminant technical consultant at Elanco Animal Health, said now is a good time for farmers to review their blowfly protection plans.
“This is a reminder that blowfly risk can build quickly and is already present in areas where farmers may not be expecting pressure yet,” she said.
“The warmer conditions we’ve seen through early spring mean risk is already widespread. Once temperatures rise above 9°C, blowfly activity can begin, and we are seeing those conditions earlier that we would have experienced five to ten years ago.”
According to a recent survey of 360 sheep farmers by Elanco Animal Health, 87% of UK sheep farmers saw at least one case of blowfly strike last year, with 70% of reported cases occurring before shearing.
Ms Hogan said sheep with full fleeces can be particularly vulnerable during the pre-shear period, especially when mild and wet weather create favourable conditions for strike.
“This is the point in the season where farmers can easily get caught out and even a single case of blowfly strike carries considerable welfare and production costs,” she said.
“Applying an IGR treatment early in the season not only protects sheep but can also help reduce the number of blowflies breeding and contributing to pressure later in the summer.”
Ms Hogan said the most appropriate treatment will depend on whether farmers are protecting ewes or lambs, how close sheep are to shearing or sale, and how long cover is needed for.
“For adult sheep ahead of shearing, CLiKZiN is a practical option because it provides eight weeks’ protection, which is often enough to cover the pre-shear risk period,” she explained.
“It also has a seven-day meat withdrawal period, making it suitable for short-keep lambs where appropriate.”
Where ewes have already been shorn, or for lambs remaining on farm for longer, Ms Hogan said CLiK EXTRA may be the more suitable option, offering 19 weeks’ protection with a 40-day meat withdrawal period.
“The key message is to treat based on risk, not routine,” she added.
“The SCOPS forecast can help farmers identify when pressure is building locally and make timely decisions before strike becomes a welfare and productivity issue.”
