Keeping fly numbers under control is essential for protecting cattle health, reducing stress, and preventing production losses. Use this checklist as a quick reference during the grazing season.
1. Identify the Fly Species
Horn Flies
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Location: Back and belly
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Treatment threshold: ~300 flies per animal
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Best control: Ear tags, sprays, pour-ons, insect growth regulators (IGRs)
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Tip: Rotate chemical classes to avoid resistance.
Stable Flies
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Location: Legs and belly
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Treatment guideline: ~5 flies per leg
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Best control: Sanitation + targeted sprays
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Tip: Clean up spilled feed/hay and dry out wet areas.
Face Flies
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Location: Around eyes, nose, and mouth
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Concern: Transmit pinkeye (Moraxella bovis)
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Tip: Reduce eye irritants (tall weeds, coarse hay) and consult your vet at first signs of pinkeye.
House Flies
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Location: Around feed areas, on animals, and manure
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Concern: Can worsen existing pinkeye cases
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Tip: Maintain sanitation to reduce breeding sites.
2. Maintain Pasture and Feeding Area Sanitation
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Remove or spread manure regularly.
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Clean and dry hay-feeding sites.
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Eliminate old feed piles and wet organic matter.
3. Apply and Rotate Control Products
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Always follow label instructions.
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Use a mix of control methods (tags, sprays, pour-ons, mineral with IGR).
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Rotate chemical classes annually to reduce resistance.
4. Monitor Effectiveness
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Check animals weekly for fly counts.
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Reapply products after heavy rainfall if needed.
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Replace fly tags after 90 days or as recommended.
Tip: A proactive, integrated approach — sanitation + targeted chemical use — delivers the best results and minimizes long-term costs.
