Control Profit-robbing Flies

Key Takeaways

• Four major fly species – face flies, horn flies, house flies and stable flies – significantly reduce cattle productivity and cost producers millions each year.
• Face flies spread pinkeye-causing bacteria and reduce grazing, leading to major losses in calf weight and market value.
• Horn flies take multiple blood meals per day, decreasing feed intake, weight gain and milk production, costing the U.S. industry over $1 billion annually.
• House flies and stable flies are major threats in confinement settings, transmitting mastitis-causing bacteria and triggering reduced feed intake, bunching, irritation and weight loss.
• Effective fly control requires consistent use of insecticide ear tags, pour-ons, sprays, baits, dusts and environmental management to protect herd health and producer profitability.

Flies are much more than a nuisance. Their economic impact can reach deep into a cattleman’s pockets.

In cattle production, from beef to dairy operations, there are four key fly species affecting profitability across the industry: face flies, horn flies, house flies and stable flies. For pasture cattle, producers should ensure their herd is protected from face flies and horn flies. For cattle fed in confinement, the house and stable fly are the most critical offenders to shield from cattle, and a producer's pocketbook.

Learn more below about each profit-robbing fly species impacting the industry, as well as key indicators and prevention methods. 

Face flies

Face flies can cause reduced grazing and weight loss. These flies also transmit the pinkeye-causing bacteria known as Moraxella bovis and bovoculi, plummeting profit by as much as $12 per hundredweight, compared to healthy calves sold without pinkeye.

- Watch for: Flies on the faces of livestock, especially around the eyes and muzzle
- Protect through: Insecticide ear tags, pour-on, spray, bait and dust

Horn flies

U.S. livestock producers lose $1 billion annually because of the horn fly, due to decreased feed intake, weight loss and diminished milk production. A single horn fly can take a blood meal from a calf up to 30 times a day. The impact on rate of gain for yearlings is colossal, reducing weight by 18%. That’s not all; horn flies also are linked to mastitis outbreaks.

- Watch for: Flies on the backs and sides of cattle, tail switching, visible irritation
- Protect through: Insecticide ear tags, pour-on, spray, bait and dust

House flies

Mastitis costs dairy producers $2 billion per year, with a single mastitis case costing nearly $450 per cow. Like the horn fly, the common house fly also transmits mastitis-causing bacteria. The house fly causes aggravation in cattle, pen avoidance and reduced feed intake.

- Watch for: Constant cattle movement, bunching, tail switching, flies on structures and animals near feed
- Protect through: Insecticide ear tags, pour-on, spray, bait and dust

Stable flies

Costing producers $2.2 million every year, stable flies can cause blood loss, reduced milk production and decreased weight gain by as much as .48 pounds per day. Additionally, stable flies can reap havoc with pasture cattle as they bite their legs, sending the cattle to stand in a pond or causing the herd to bunch-up in the corner of a pasture. Stable flies also can be a real menace to show calves around the barn.

- Watch for: Flies on lower legs of cattle, stomping or bunching, constant cattle movement
- Protect through: Insecticide ear tags, pour-on, spray, bait and dust

It is crucial for producers to leverage effective insecticides and fly control methods to keep well-deserved dollars in their pockets. A variety of products are available to control flies, including on-animal treatments, facility and environmental treatments, as well as feed-through products.

Data above provided by Elanco

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