Early shearing advised as blowfly strike season starts
© Tim Scrivener Farmers have been advised to shear sheep early to help prevent blowfly strike, as changing weather patterns and a warm spring have led to the blowfly season starting sooner than usual.
Blowfly strike is a major economic concern for farmers, with considerable prevention costs involved for all at-risk sheep.
Affected sheep have disrupted grazing patterns and rapidly lose weight, especially if untreated for several days.
See also: Amber blowfly warning as warm weather triggers season
In warm weather, eggs laid in the sheep’s fleece can hatch quickly, with damage caused by maggots feeding on the skin in as little as 24-36 hours.
The National Animal Disease Information Service also highlights it is a major animal welfare concern.
An average of 1.5% of ewes and 3% of lambs in the UK may be affected each year, despite preventative measures undertaken by most farmers.
This number will be much higher if no control measures are adopted.
Elanco ruminant technical consultant Matt Colston said: “Administering an insect growth regulator can help control blowfly damage and associated losses by preventing the development of the damaging second and third stage larvae.”
In addition to a comprehensive treatment plan, a close and even shearing can provide an added level of protection.
“It allows blowfly treatment that has been applied after shearing to grow with the fleece,” explains sheep shearer Hefin Rowlands.
Welfare benefits
Shearing early can also help with reducing heat stress. “A common misconception is that sheep with an inch or more of fleece will be less able to cope with heat,” said Mr Rowlands.
“In fact, the presence of a relatively thin fleece in summer helps the sheep to regulate its temperature and protects its skin from direct sunlight.”
Shearing, he said, is also beneficial to lambs and can improve growth rate by encouraging higher dry matter intake.
“Shearing when lambs are below 35kg can increase growth rates by about 20 grammes a head a day, which will have a significant benefit to overall weight gain.”