Integrated Pest Management on the Dairy

 By Jaclyn Krymowski for American Dairymen

 With warmer months on the near horizon so comes the scourge of summer pests. Flies and other insects are an inevitable part of farm life. They can be a serious nuisance to you, your animals, employees and even the neighbors. More than that, they are also prime vectors to carry some nice diseases through your herd, across local farms and even to your family. An overabundance of flies in the milkhouse and parlor can even run the risk of increasing bacteria in your bulk tank. In the same vein, irritation from bites can decrease production and efficiency per animal.

When ignored and unchecked, an infestation can easily grow and spiral out of control. While no effort is a surefire way to eliminate any and all nuisance pests from your farm forever, there are lots of practical management practices you can employ to greatly reduce numbers and their impact.

What you’re up against
There are several species of flies that make themselves right at home in the barnyard. The two primary culprits usually causing the most irritation tend to be house flies and stable flies. Other species, depending on your location and seasonality, include horn flies, face flies, deer flies and bot flies among others. Females of any species are capable of laying hundreds or thousands of eggs per day.
Flies prefer to lay their eggs in wet and decaying organic matter, including fresh, undisturbed manure. There is a super-abundance of these types of locations all over the farm. And while some basic management and removing waste certainly helps, this type of environment will inevitably always be somewhere. Some research has determined even one pound of wet manure has the potential to sustain and produce over 1,500 maggots. Put that into perspective. It takes very little for even the smallest area to be a haven for fly production. Therefore, doing the barebone hygiene basics won’t be enough to keep ahead of the population. You will need to incorporate a few additional components to create a formal integrated pest management (IPM) system.

Using cultural control methods
Think of cultural control as just one branch of your IPM. This looks at the culture, or environment, on the dairy that is supportive of pest proliferation. Without having an attitude of cultural control, you won’t see maximum results in the other methods you deploy.
Sanitation is key here. The majority of your flies are coming from areas of confinement and in bedded packs. Your freestalls and alleys that get raked and scraped twice daily aren’t causing much proliferation. The “problem” areas are places of storage or animal confinement that don’t get cleaned quite so frequently.
In conefinement settings, it is recommended you scrape them clean at least once a week. This includes calf hutches, sick pens, maternity barns and anything else that sits on a bedded pack. Stores for manure solids that go undisturbed and untreated for long periods of times are also suspect, especially if they are near the barns and other buildings.
Feedbunks that sit with spoiled silage and other feed wastage that isn’t properly disposed of are also breeding habitats. Remember to also regularly check around the silos and other storage areas that may be harboring bad feed.
There are certain areas where adult flies will be attracted and cause irritation. A good idea is to establish “fly-free zones” in places of importance, such as in the milkhouse and parlor. Remember to keep these places free of any sort of attractants. Installing window and door screens (or replacing damaged ones) may help with this. Adding a few extra fans can also be helpful in creating an unsavory environment for flies to congregate.

Using biological, chemical and physical control methods
Some farms have found much success incorporating natural fly predators into the dairy environment. These may include black soldier flies, red-tailed maggots, parasitic wasps, beetles and mites. Coupled with good sanitation practices, establishing a healthy population of one of these biological predators can have a major impact on the pest population.
Chemical controls include sprays, mists, baits and larvicides. There are also insecticide ear tags and larvicide feed additives. Certain larvicides can be added to manure stores, but be aware that if you are using biological predators, this will impact their populations as well. This type of treatment is typically recommended for use in areas that can’t be eliminated regularly by basic sanitation, such as your long-term stores. However, it is important to note that house flies can gain resistance very quickly. Be sure to use chemical controls deliberately and with discretion according to the instructions.
Likewise, if you keep knockdown sprays on hand for those irritating adults buzzing around the working areas, be sure to only use ones that approved and labeled for use in and around dairy facilities.
There are a variety of traps and baits that can be used to further eliminate flies in high-traffic areas. While they won’t be super effective at making a huge dent in the larger population, they are excellent at managing specific areas.
Another physical method are your fans. Fans are not only an important part of cooling and cow-comfort, but they can also be an aid to relieve fly stress and irritation. Take a look at your fan placement and air flow. This should include not only your freestall areas, but also the holding pen, sick pen and calving pen.
The battle against buzzing insects is one of those inevitable summer frustrations. Investing in a little conscious effort and the right tools will have you feeling at least some control over the situation. Your employees and cows will thank you!