Flies cause significant welfare harm to cattle through irritation, disease transmission, and energy expenditure on avoidance behaviour. Integrated fly management protects cattle welfare in summer.
Fly-related welfare problems in cattle are easily overlooked but cause real suffering and productivity impacts. Cattle heavily infested with horn flies or face flies spend significant energy and attention on avoidance behaviours — bunching, head-shaking, tail-switching, and reduced grazing — rather than productive feeding. The resulting stress and reduced feed intake impair growth and milk production. More direct harm includes blood loss from biting flies and disease transmission via eye infections. Integrated fly management that combines rotation-based pasture management, biological control, and targeted chemical use where necessary provides effective welfare protection.