With warm weather flies become more than just a nuisance – they can significantly impact the health, comfort and productivity of your herd. During the warmer months, controlling flies is an important part of maintaining animal welfare and maximizing farm profitability.
The two most common flies affecting dairy cattle are:
- House flies – feed on secretions around the eyes, nose and wounds and contaminate feed and equipment
- Stable flies – bite cattle, causing pain and stress by feeding on blood, especially around the legs
The hidden cost of flies
- Reduced milk production
- Lower feed intake
- Stress and discomfort
- Reduced weight gain in young stock and beef cattle
- Poor reproductive performance
- Spread of diseases (pink eye, mastitis and other bacterial infections)
Cows will spend valuable time stomping, kicking, tail swishing and bunching together instead of grazing, eating, ruminating or resting.
Fly control
It is better to start fly control early in the spring before fly numbers increase. Waiting until flies become a problem makes them much harder to control. The best fly control program combines several methods:
- Eliminate breeding areas: flies reproduce quickly in moist organic matter
- Remove manure regularly, keep bedding clean and dry, repair leaking waterers, clean spilled feed, ensure good drainage around the barn
- Use fly control products
- Pour-on insecticide, ear tags, premise sprays, fly baits, larvicides etc.
- Rotate insecticide classes each season to reduce insecticide resistance
- Reduce fly pressure
- Use fans to improve air movement – flies are weak fliers and avoid strong airflow
- Rotate pastures to avoid excessive manure buildup around feeding areas
- Monitor your herd
- Watch cattle for signs such as: constant tail swishing, stomping feet, head shaking, skin twitching and cows bunching together
Not all fly products work the same way and choosing the right program depends on your herd, housing system and fly pressure. Talk to your herd vet or call the clinic if you have any questions.