You need to know the weight of the animal being fed and the amount of feed consumed each day by this animal. Ear Tags Insecticide-impregnated ear tags have been approved for use on dairy and beef animals. Be sure tags are attached correctly. They are very effective in controlling horn flies, only moderately effective in reducing numbers of face flies, and are much less effective against house and stable flies. Currently there is no practical control for deer and horse flies or mosquitoes.
Face flies are also difficult to control.
However, the horn fly is easy to control, and the farmer has a choice of insecticides. These products can be applied by spray, backrubber or self-treating dust bags. While flies generally do not bother hogs, chickens, and rabbits, and horses and dogs are not involved in human food production, fly control is still important. Flies are considered a public health nuisance and health authorities can force you to take action. If you are involved with these animals, recognize your responsibilities.