When it comes to fly prevention these are steps that all producers should consider to keep fly problems to a minimum. Biting flies can carry diseases such as anaplasmosis and bovine leucosis virus. Face flies can spread Moraxella bovis, which cause pinkeye, from animal to animal. The economic loss from each horn fly bite over 20 times a day can also add up. Listed below are steps to help you reduce fly in your herd.
1.) Feed a larvicide or a insect growth regulator like Altosid (labeled for horn flies) to cows, starting 30 days before flies typically emerge. Continue 30 after a killing frost.
Clarifly is also a option, but it is mainly used for confinement cattle. If an adjacent property also has cattle, the owners of those cattle also need to feed the product to their herd or you may inherit some of the neighbor's flies. Horn flies don't travel long distances, but face flies may travel 1-3 miles.
2.) Fly Tags. Fly tags have come a long way recently and they contain higher concentration of insecticide which is helpful in controlling fly populations.
Many tags require two tags/adult animal and one tag/calf for optimum control. The key to using fly tags is to wait until you have several hundred flies per cow to place the tag. If you apply to early, you'll have decreased efficacy, also be sure to remove tags in 4 months, in order to prevent resistance issues.
3.) Pour-ons. Use a pour on at the same time you fly-tag the cows. If it's spring turnout time, you can use a product that also kills internal parasites, as they products also have efficacy against horn flies. Later in the year, use products only labeled for flies and/or lice. Using pour-on dewormers many times throughout the year could lead to internal parasite resistance issues as well.
4.) Dust Bags/cattle rubs. Place it at a site where all cattle must use it, it can provide a very economical control of face and horn flies. Proper placement and keeping it charged with insecticide is the key.
5.) Sprays. Timely spraying of cattle throughout the year can be effective in reducing the fly population, but can be time consuming if cattle are grazing in a huge pasture.
There are many products on the market for fly control. Come in and sit down with one of our staff and develop a plan to control flies.
Remember, you can't eliminate fly problems, but you can lessen their negative impact.