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Fly Control

Apr 18, 2021

Are flies bothering your calves? Usually from May through October flies can be a problem for your livestock operation. Flies are an irritant to livestock and farm workers.

Bites can be painful and cause restlessness in calves. Along with that, calves are less likely to consume feed/milk with flies on it and flies can be a source of disease spread such as pinkeye. In order to prevent flies from negatively impacting productivity, fly control in livestock operations is essential.

Preventing a population buildup is easier than controlling established populations. Here are some proactive steps to control flies before your operation is heavily infested:


Leaky water troughs, wet hay or straw, spilled feed or milk, and overgrown vegetation can result in increased fly breeding. Repairing leaky plumbing and promptly removing the wet hay or straw will aid in preventing large buildups of fly populations. Bedding may need to be cleaned out more frequently during summer months to ensure it stays dry. Tall weeds around pens and buildings need to be maintained because they often hide spilled feed and manure, as well as hinder the drying of wet areas.

Fans can disrupt flies in dry damp areas. Ensure any milk or milk replacer is immediately cleaned up, not left out where it will attract flies. Garbage cans should be covered as well as emptied and cleaned frequently.


ClariFly can be added to calf feed and milk replacer. It has an active ingredient that controls house, stable, face, and horn flies. The active ingredient targets immature flies by either contact or ingestion. Therefore, the larvae die before they can become breeding adult flies. Contact the coop if you’d like ClariFly added to your mix or replacer this fly season.


Sticky tape or traps are effective in controlling minor fly infestations if placed where flies congregate. However, the downfall is that these must be changed frequently. Ensure that sticky traps are placed well out of reach of animals.


Insecticides may be necessary in moderate to high levels of fly infestation. Always make sure you read and follow label directions on chemical fly control products. Talk to the dealer or your herd veterinarian to ensure that chemicals used in your operation are safe for animals and don’t serve as a food safety risk. Continuous use of sprays may result in resistance, so products should be used sparingly and only as needed.

Overall, it is essential to control the breeding sites of flies before taking any other pest control steps. If the breeding sites are not managed, attempts to control infestation will be ineffective.

Ask your Countryside-Landmark rep about our Calf X product line containing fly control. The 18% starter, 20/20 & 24/17 milk replacers have ClariFly to help during fly season.

Courtney Crave
Feed Products Specialist