Management of Horn Flies and Stable Flies: A Strategy to Maintain Performance in Dairy and Beef Cattle
With the warming of weather in spring and summer, fly populations in livestock farms increase rapidly and become one of the most important factors reducing animal comfort, health, and productivity. Among the various fly species associated with livestock, the horn fly and stable fly are considered two of the most economically important pests in dairy and beef cattle. In addition to causing stress and irritation, these insects can reduce feed intake, weight gain, and milk production (Taylor et al., 2012; Merck Veterinary Manual, 2024).
The horn fly (Haematobia irritans) is a small blood-feeding fly that spends most of its life on the cattle’s body. It feeds on blood multiple times per day, and at high infestation levels it can cause restlessness, reduced resting time, and decreased animal performance. Studies have shown that severe horn fly infestation can lead to reduced average daily gain in beef cattle and decreased milk production in dairy cows (Byford et al., 1992; Campbell, 2006).
The stable fly (Stomoxys calcitrans) is also one of the most important pests in livestock operations. Unlike the horn fly, which remains mostly on the animal’s body, the stable fly typically feeds on the lower parts of the body and legs, causing painful bites and frequent defensive behaviors in cattle. Foot stamping, constant leg movement, and clustering of animals in certain areas are common signs of infestation. These behaviors reduce feeding time and increase maintenance energy expenditure (Foil & Hogsette, 1994; Taylor et al., 2012).
Successful fly management must be based on a preventive and continuous program. The first step is reducing fly breeding sites. Manure and moist organic materials provide ideal conditions for larval development; therefore, regular manure removal, improved drainage, and preventing moisture accumulation around waterers and feed bunks can significantly reduce infestation pressure (Hogsette, 1993; Merck Veterinary Manual, 2024).
Along with environmental management, the use of mineral supplements containing insect growth regulators (IGRs) is an effective method for controlling horn flies. After ingestion by the animal, these compounds are excreted in the manure and prevent larvae from developing into adult flies. In this way, the fly life cycle is interrupted at the breeding site, and populations are controlled throughout the season (Sheppard, 1987; Kaufman et al., 2021).
Proper nutrition also plays an indirect but important role in mitigating fly-related stress. Animals receiving balanced diets and adequate mineral supplementation have greater ability to cope with environmental stress and maintain production performance. Supplying trace minerals such as zinc, copper, selenium, and manganese supports skin health, immune function, and resistance to stressors (NRC, 2021; Spears & Weiss, 2014) (chelated mineral supplement).
Targeted use of insecticidal ear tags, sprays, and pour-on formulations can also be part of a fly control program. However, experts recommend implementing these methods within an integrated pest management (IPM) system to reduce the risk of resistance development in fly populations (Taylor et al., 2012; AAEP, 2023).
Ultimately, successful fly control is achieved when farmers act before fly populations reach high levels. Waiting until severe infestation occurs is usually associated with reduced performance, compromised animal welfare, and increased production costs. Combining environmental hygiene management, appropriate mineral supplementation, and targeted control programs can help maintain herd health and farm profitability during the warm season (Merck Veterinary Manual, 2024; Kaufman et al., 2021).
• AAEP (2023). Integrated Fly Control Programs for Livestock.
• Byford, R. L., Craig, M. E., & Crosby, B. L. (1992). A Review of Ectoparasites and Their Effect on Cattle Production.
• Campbell, J. B. (2006). Horn Fly Biology and Management.
• Foil, L. D., & Hogsette, J. A. (1994). Biology and Control of Stable Flies.
• Hogsette, J. A. (1993). Managing Breeding Sites of Stable Flies.
• Kaufman, P. E., et al. (2021). Integrated Pest Management for Livestock Flies.
• Merck Veterinary Manual (2024). Horn Flies and Stable Flies of Cattle.
• NRC (2021). Nutrient Requirements of Dairy Cattle.
• Sheppard, D. C. (1987). Insect Growth Regulators for Fly Control in Livestock.
• Spears, J. W., & Weiss, W. P. (2014). Role of Trace Minerals in Cattle Health and Performance.
• Taylor, D. B., Moon, R. D., & Mark, D. R. (2012). Economic Impact of Stable Flies on Cattle Production.