Fly Control and Welfare in Beef and Dairy Cattle

Flies cause significant welfare problems in cattle during summer months, including irritation, blood loss, eye damage, and disease transmission.

Key Facts

Face flies spread Moraxella bovis, the cause of infectious bovine keratoconjunctivitis (pinkeye)
Horn flies bite up to 30 times per day and reduce grazing time significantly
Cattle tail swishing, skin rippling, and bunching are behavioral indicators of fly irritation
New World screwworm is a serious exotic disease threat requiring emergency response
Integrated pest management reduces reliance on insecticide treatments

Welfare Considerations

Fly burden in cattle causes chronic stress and welfare compromise during summer months. Heavily fly-bothered cattle spend less time grazing and more time standing in water or shade, affecting nutrition and productivity. Pink eye caused by face fly transmission is painful and can cause permanent blindness if untreated. Fly strike in wounds adds further welfare concerns. Refugia-based parasite management principles are increasingly applied to fly control to prevent resistance while maintaining welfare benefits.

What You Can Do

Support farms using integrated fly management approaches rather than blanket insecticide use
Ensure pastured cattle have access to shade and water to reduce heat and fly stress
Advocate for research into biological fly control methods on farms
Monitor cattle for pink eye and fly-related lesions during summer inspections