Integrated pest management on a dairy farm has two main focuses: the first is keeping the pest out of the food product and the second is keeping the insects away from the cows. You've probably notice your cattle swatting at the flies with their tails on a hot summer day, but they can only reach so far. Remember, happy cows make tasty milk, so it's important make sure the animals aren't stressed out by biting insects.
Typically, it isn't much trouble to keep the pests out of the dairy product. As long as you're following proper milking procedures and keeping the milk sealed properly, you won't have much to worry about. Then, of course, the pasteurization process will remove anything you can't see with the naked eye.
According to Cornell University, using only insecticides to remove flies could prove to be wrong move in the long run. For instance, long-term use of chemical repellents might lead to increased resistance. It could also kill off the natural predators of the fly, effectively destroying a secondary means of control. These concerns are, of course, in addition to the safety concerns of the animals and farm workers. Excessive insecticide use could affect mammals as well - and that includes humans.
The first thing to consider should be sanitation. Simply put, if the confined areas are cleaned regularly, there's less of a chance of flies hatching. The insects like to lay their eggs in rotting materials or feces, so cleaning out these messes could mean less flies in the future. With that said, a barn is never going to be as clean as a kitchen. That's why other forms of pest control are necessary.
Michigan State University reported on a number of approved oils and tags that can be applied directly to the cattle to prevent fly bits and lice infections. Some oils need to be rubbed onto the backs of the animals periodically. There are also tags that can be clipped the animal's ear which release pest repellents that do not affect their ability to produce milk.
The pest management solution that's right for you will depend on the size of your operation and geographic location. But the main point to take away is that it is not enough to have only one control method. Multiple strategies will ensure the health and safety of the animals and the dairy product.