Cattle Fly Control and Welfare in Summer

Fly burden causes significant welfare compromise in cattle during summer months, with appropriate fly control reducing behavioral distress, disease transmission, and production losses.

Key Facts

Horn flies, face flies, stable flies, and heel flies each cause different welfare impacts in cattle
Horn flies cause significant irritation through repeated biting, with heavily infested cattle showing bunching, head-tossing, and reduced grazing time
Face flies spread pinkeye (infectious bovine keratoconjunctivitis), a painful and vision-threatening condition
Warble flies (in regions where present) cause painful subcutaneous larval migration causing distress
Fly control options include insecticide pour-ons, ear tags, face masks, and biological control
Fly-related stress reduces beef cattle growth rates and dairy cow milk production measurably

Welfare Considerations

Fly burden represents a sustained summer welfare problem for cattle that is often underestimated by producers focused on clinical disease rather than behavioral distress. Heavily fly-infested cattle spend substantial time and energy on defensive behaviors including bunching, running, and tail-swishing that reduce feeding and resting time. Pinkeye caused by face flies causes acute painful eye inflammation with risk of permanent vision loss. Effective fly control substantially reduces this burden and the associated welfare and production costs simultaneously.

What You Can Do

Implement a fly control program before fly season begins rather than waiting for heavy infestation
Use ear tags with insecticide active against horn flies in cattle with heavy persistent burdens
Provide face masks or shade structures to reduce face fly contact and pinkeye transmission risk
Treat pinkeye cases promptly with appropriate antibiotic and anti-inflammatory therapy
Rotate insecticide classes between seasons to reduce resistance development in fly populations