Season-long fly control using fly tags is helping one Wales-based producer to stay on top of summer mastitis.
TEXT SARAH ALDERTON
Fly populations will multiply rapidly as spring temperatures increase, and producers should tackle the problem early to protect their herds for the summer season. Flies spread disease, but they’re also extremely irritating and cause a high level of stress to livestock. This can impact feed intakes and, subsequently, performance, with associated drops in milk yield or daily liveweight gain typical.
Fly populations vary from season to season, with different species emerging at different times of the year. However, they often become apparent when weather conditions start warming up from early spring. A preventive approach is key for successful control, and a good rule of thumb is to treat cattle before flies appear to get on top of the problem.
Flies have always been a problem at Shordley Hall Farm, near Wrexham, home to Richard Pilkington’s pedigree Holstein herd. Until recently, flies were controlled using a pour-on product, which was applied every three weeks throughout the summer and into October. But when Mr Pilkington decided to switch from housing cows all year round to grazing from early spring to autumn in 2020, this made regular pour-on applications challenging. The autumn-calving herd comprises 260 milkers, plus 300 followers, as well as 100 dairy beef cattle finished and sold on a deadweight basis. All are now protected against flies using Flectron fly tags, which are fitted in early June.
Before using the tags, Mr Pilkington would typically see a handful of heifers calve down each year that had lost a quarter due to summer mastitis, with the transmission of mastitis infection caused by the head fly.
He’s also seen cases of New Forest Eye into double figures, with more than 10 cases often seen a year. But since switching to using the tags in 2021, it’s rare to see any cases – he’s seen just a couple during the past year. The tags work by slowly releasing the active ingredient, cypermethrin, onto the tag’s surface. The tag acts as a constant reservoir of insecticide throughout the season. The active ingredient binds to the sebum or natural oil present in the animal’s coat and skin surface. Body movements such as grooming and rubbing against other cattle transfer the insecticide onto the hairs of the coat, and this disperses the active ingredient across the animal, effectively offering whole-body protection against flies within 24 to 48 hours of the tag being fitted. The binding of the cypermethrin onto the sebum ensures a high degree of rain fastness too. This means when flies come into contact with the tagged animal, they will die within a few minutes.
There was a noticeable difference in fly numbers in 2021, and the cattle were noticeably quieter. “Although we don’t have any data to back up the production benefits, the cattle were definitely more settled and, achieved better growth rates as a result of not being disturbed by flies.
“The convenience of only having to treat cattle once to cover them from early summer through to the autumn and the peace of mind knowing that they’re protected, are also significant benefits,” adds Mr Pilkington. This tag is the only product that ensures season-long control, meaning there is no need to re-treat. It covers cattle for up to five months with no meat or milk withdrawal period. Fly lifecycles are completed extremely quickly, giving rise to rapid population expansions, and highlighting the need to apply fly control medicines early in the season. Different fly species emerge at times of the year (see Figure 1).
“When selecting a product it is essential to know what fly species it protects against,” says Zoetis vet Ally Anderson. “Flectron protects against both nuisance and biting flies. The key to good fly control is to get on top of the problem before it becomes a big issue. Flies can reproduce in large numbers in a short period of time, so it doesn’t take long for fly populations to expand once they are present. “Fly-related diseases can be prevented with the early use of fly-control products and by following by farm hygiene protocols. Each product may have different active ingredients, control periods and withdrawal times,” says Ms Anderson. “It’s important that producers discuss insect control options with their vet or qualified animal health adviser to find the product most suited to their herd,” she adds.
● Provides season-long control, so there’s no need to re-treat. This reduces labour and minimises production losses associated with handling
● Helps to reduce fly population growth
● Ideal for grazing cattle
● No milk or meat withdrawal
● Easy to use and suitable for cattle of all ages
● Protects against both nuisance and biting flies