Flies are more than a nuisance on dairy farms. They can reduce the productivity your herd by adding stress, and they can transmit diseases such as pinkeye and mastitis. As summer approaches, here are some tips for their control:

 

• Don’t wait for heavy fly populations to develop. It is much easier and less expensive to prevent fly populations from increasing at the beginning of the season.

• Practice good sanitation. A clean facility has fewer fly problems.

• Remove all manure from livestock pens as frequently as possible. Pens with calves or bulls require special attention and should be cleaned once or twice a week.

• Manure that has been removed should be spread thinly on fields or other large outside areas to facilitate rapid drying, which will help kill developing fly eggs and larvae. Another option is to stack the manure and cover it completely with black plastic.

• Eliminate silage seepage areas, wet litter, manure stacks, old wet hay or straw bales, and other organic matter accumulations that may attract flies.

• Read and carefully follow all pesticide label directions.

• Provide proper drainage in barnyards. Use clean gravel and other fill to eliminate low spots in yards. Proper tiling can reduce wet barnyards.

• Combine routine sanitation with a variety of pesticide strategies such as baits, residual sprays, space sprays, and larvicides whenever flies are a problem.

• Make certain any pesticide selected for fly control is approved for use in lactating dairy animals.

• For maximum effectiveness, use chemicals that abort the larval stage as well as chemicals that kill adults.

• Reduce pesticide resistance problems by alternating use of products according to their modes of action.

• If using eartags to control flies, replace them as their effectiveness wanes. Remove eartags at the end of the fly season.

• Frequently check and replace chemicals used in exit lane dusters or pasture back rubs.

• Monitor and maintain all pesticide applicator equipment.