Controlling cattle flies has always been troublesome and difficult.
It is about reducing fly populations, not elimination. The goal is to limit the negative economic impact that flies can cause. Three main fly species can economically impact pastured cattle and those are the horn fly, the face fly and the stable fly, according to Drovers CattleNetwork.
Horn flies are small and are blood feeders. Each fly will bite the animal 20 to 30 times per day. Losses from the horn fly are estimated at more than $800 million per year, which includes decreased grazing efficiency, blood loss, reduced weight gains and declines in milk production.
The face fly is a non-biting fly, but feeds on secretions, nectar and manure liquids. They cluster around the animal’s eyes, mouth and muzzle and can cause pinkeye, tissue damage and an open pathway for pathogens.
Stable flies give a painful bite, which lowers weight gains. Estimated loss is more than $2.4 billion each year.
The recommended control technique is horn fly ear tags, which should be not be put on until flies reach the economic threshold level of 200 flies per animal. Tags should be removed when fly levels decrease. Ear tags are also a common form of control for face flies. The best control for stable flies is dependent upon sanitation, including the cleaning of breeding and larval sites.