Late in the summer and late in the fly season, flies on beef cattle seem to still be a problem in many areas. Flycontrolcenter.com indicates horn and face fly numbers can continue to build throughout the summer, so now is a good time to check your cattle for flies and evaluate the effectiveness of your fly control program. The best time to check is early afternoon on a sunny day. Your goal is less than 100 flies per side and less than 10 face flies per head. If your numbers are higher, consider changing your program and using some of the following recommendations.
An integrated approach is usually necessary and begins with adding new fly tags, as ones that are attached early in the season are probably running out by now. It is a good idea to use a different chemical in the tags than you used in the previous tags. Feed-through insecticides in mineral supplements require a minimum daily level of consumption by each animal and work by controlling hatching of fly eggs on manure. These products are effective if you have been using them starting in the spring, but it does require some time before you see a difference in fly numbers with feed-through fly control. Dust bags, back rubbers and oilers are effective but make sure they are fully charged and keep the dust off so they will be effective. Pour ons and sprays are effective short term but really only last a few weeks. If you do use a pour on or spray, make sure you use a different chemical in case some resistance has occurred to the old product. If you are having fly problems with your herd, contact your veterinarian or university agriculture extension for a referral to an expert on fly control in your area.