Protecting livestock against flies this spring is important to prevent major production losses. So says Zoetis’ vet Dave Armstrong, who adds that although flies may not become an apparent problem in stock until early summer, treating before high numbers are seen will make control easier and more effective.
“Early detection and treatment is vital to successful fly control. By the time you notice cattle being troubled by flies, a population explosion is already taking place. When flies take hold then it’s harder to get them under control.”
Flies not only irritate livestock, but they can cause major economic losses due to reduced feed intake, which impacts on productivity. And flies can also transmit diseases, such as pink eye, summer mastitis, Schmallenberg, and Bluetongue.
Studies have shown that, in cattle, fly ‘worry’ can cause milk yield losses of up to 0.5 litres per day.
Three main types of flies
There are three main types of flies that affect livestock - nuisance, biting and strike flies. Different fly species appear at different times of the year meaning they are a constant threat.
In addition to treatment, Dr Armstrong suggests that producers also take steps to reduce favourable environments for flies. These include:
- Keeping manure dry and compacted, and turning every two to four weeks
- Improving ventilation in sheds
- Keeping livestock away from fly breeding sites, such as wet and muddy areas