Flies: More Than Just a Nuisance for Cattle

Written by: Simon Kern, M.S.

While the calendar may be telling us there are still a few more days of winter, it’s hard to deny it feels very much like spring across much of the Midwest. While spring may bring green grass and warmer temperatures, it also brings back one of the nastiest enemies known to the cattle industry. Flies. While those stray flies buzzing around our homes may seem like just a common nuisance, flies cause over one billion dollars of damage to the North American cattle industry annually. This is largely through the transmission of more than 65 known diseases! Flies are largely to blame for the spread of pink eye which alone causes losses to the U.S. cattle industry totaling $150 million. Flies also cause a decrease in feed efficiency. With only five stable flies per leg, flies are creating a sizable loss of $8.50 per cow per season due to decreased feed efficiency.

Cattle producers are not without a few tools in their tool belt when it comes to fighting the annual fly onslaught. One of these tools is feed-through fly control technologies. Feeding these products causes a disruption in the fly life cycle in the manure of treated cattle. Despite the effectiveness of these compounds to kill flies, they are extremely safe to feed to cattle due to their specific mode of action. Clarifly®, RabonTM, and Altosid® are the three feed-through fly control products available on the market today. Though they may each target a different stage in the fly life cycle, they are all highly effective at stopping flies at their source. Clarifly and Rabon are the go-to options for confined cattle as they both control multiple fly species. Also, both Clarifly and Rabon have very specific feeding rates based upon animal bodyweight which makes them ideally suited for force-feeding rather than free-choice supplementation. On the other hand, Altosid is a great fit for cow-calf producers in a pasture or grazing production system. Altosid controls horn flies, the primary fly species afflicting cattle on pasture, extremely well. Additionally, Altosid can be fed at a wider range of intake levels, making it the logical choice for free-choice supplementation.

Early implementation prior to the appearance of a large fly population as well as full season follow-through are a must to have an effective measure of control. While these technologies are highly effective in treating the manure of treated cattle, it is critical to remember that flies do not only develop in manure. Untreated feed or feed ingredients as well as standing water and mud are all great places for flies to develop. Also, flies can easily travel several miles (especially downwind), so be mindful of neighboring farms with less than ideal fly control measures.  Feed-through fly control technologies should be thought of as just one of the tools in a comprehensive fly control program which should also include pen management, general farm cleanliness, and premise spray treatments.

Contact your Form-A-Feed representative to find out more about fly control practices and how they can best be implemented on your operation.