We’re buzzing about fly control!

With the days lengthening and the weather turning warmer, it’s great to see cattle being turned out and enjoying the sunshine. However, unfortunately that also means that fly season is here with all the unwelcome irritation and nuisance that flies cause to both livestock and workers.

There are numerous types of flies, but the main ones affecting UK livestock are stable, horn, house, face and head flies. Although fly varieties and populations will differ from farm to farm, they can cause substantial production losses in any management system by causing issues such as:

  • Spread of bacteria that cause Summer Mastitis (the average cost of a case being £250-£300 according to AHDB) and Infectious Bovine Keratoconjunctivitis (New Forest Eye/ Pink Eye)
  • Irritability in the milking parlour – kicking, tail swishing, dunging. This irritation can also affect those working with the cattle.
  • Distraction from eating leading to weight loss, reduced daily live weight gain and reduced milk yields
  • Compromised cattle welfare due to constant irritation

So, what are the options for fly control?

Control strategies will vary from farm to farm depending on the type of production system, housing/grazing and location. Options to consider include:

  • Environmental and stock management
    • Avoid grazing on wet, low lying fields near woodlands during the summer months
    • Control/removal of fly breeding grounds e.g. waste silage, muck heaps, pooled water/slurry
    • Use of fans in buildings
    • Use of teat sealants, especially in dry cows and heifers
  • Chemical management
    • There are a variety of insecticides licensed for the control of flies in cattle that come in the form of topicals, aerosols and injectables.
    • These chemicals can be unpleasant to handle and potentially hazardous to the people using them (e.g. when spraying large quantities around the parlour)
    • Meat/milk withdrawal periods need to be considered
    • There is also evidence that resistance can develop to some of these chemicals, which can result in their effectiveness decreasing.

Forward planning…

From both financial and welfare points of view, we know that prevention is always better than cure. With this in mind, as nuisance flies typically start breeding anytime from March onwards, it’s well worth putting measures into place to tackle them now before they become more of a problem. If using insecticides, applying these early in the season (before flies are already bothering cattle) can reduce the first wave of attack and reduce next generation numbers.

Introducing a new, natural alternate approach… ‘Friendly Flies’!

Flies suffer with parasites just as mammals do, and these parasitic wasps can enable farmers to take a pro-active, cost effective approach to fly control that reduces reliance on chemical solutions and decreases fly population on farm. These little insects have been around in the UK for quite a number of years now but are still somewhat unheard of in the agricultural industry. Importantly, they target only the biting and nuisance flies that commonly affect UK livestock; bees, butterflies and other insects are left unharmed. These parasitic wasps kill nuisance fly larvae before they have even hatched; therefore, they can be used much earlier in the season than chemical preparations.

Spalangia cameroni on a fly pupa

With parasites, the greatest benefits are seen when they are used regularly, and for the first few years it is beneficial to use in conjunction with more traditional approaches. This allows a build-up of parasitic wasps and suppression of breeding numbers of the nuisance flies. One study conducted in Argentina recorded a 90% reduction in fly population when compared to untreated control farms! They have also been successfully used on UK pig and poultry farms.

Here at Westpoint, we’re really excited about this new, sustainable option for fly control and we’d be more than happy to discuss further details if you are too.

To discuss strategies for fly control on your farm or if you would like more information on Clover Friendly Flies, please contact your local Westpoint practice and speak to a member of the team.