Why Your Fly Control Strategy Should Include Feed Additives

FBN Network

Apr 10, 2024

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As summer approaches, it’s a good time to start thinking about adding fly control solutions to your nutrition program. 

The newly released FBN® Grass Turnout Guide provides an essential overview to help producers prepare their cattle for grass turnout, including preventing and managing flies. Access your free digital download here

Below, we’ll cover:

  • Why Fly Control Is Critical for Your Profitability

  • Develop a 3-Step Fly-Control Strategy

  • Feed Additives to Consider for Fly Control 

  • Get the Fly Control Products You Need to Be Proactive

Why Fly Control Is Critical for Your Profitability 

Flies are more than simply an annoying nuisance. Ignoring the problem can have a significant impact on both your herd’s health and your operation’s finances. 

“During peaks, as many as 4,000 horn flies can call a cow’s hide home. At 30 blood meals each, that adds up to 120,000 bites per cow per day,” explains Purina Animal Nutrition. “Not only are these flies irritating your cows, but with production losses for the U.S. cattle industry estimated up to $1 billion annually, they’re also biting away at your profits.” 

Even significantly fewer numbers of flies can have a negative impact on livestock. Fly counts of 200 flies per animal will require a systematic plan to eradicate the infestation.

Reducing flies is possible, and starting early is beneficial. As we reveal in the FBN Grass Turnout Guide, for every one fly you eradicate in April and May, there will be 80,000 fewer of them in August and September.

Develop a 3-Step Fly-Control Strategy 

While there is no one single way to deal with fly control, the best strategy is to tackle the issue with a multifaceted approach.

1. Understand Fly Types

Having a good understanding of the different types of flies can help you develop an effective strategy for fly control. The four major fly types that impact livestock are:

  1. Face flies

  2. House flies

  3. Horn flies

  4. Stable flies

Learn about fly life cycles, where they’re commonly found, and how they impact livestock in the FBN blog “Effective Fly Control: Knowing the Different Types of Flies.”

2. Start with a Clean Space 

Whether you’re dealing with feedlot, cow calf, dairy cattle, or a swine operation, a critical step in any fly control program is to clean up areas where your livestock congregate — and where flies likely breed.

Removing stock-piled manure or spilled feed and silage on a weekly basis is a simple preventative measure that will help keep flies from becoming a problem for your animals.

It’s also a good idea to cut or mow vegetation to less than five inches to prevent flies from overtaking your livestock.

3. Incorporate Feed Additives for Fly Control

Incorporating feed additives is a smart and effective way to curb fly infestations.

Start including fly control additives in your feeding program early in the spring, usually about 30 days before the average daily temperature reaches 65 ℉ or when flies begin to appear.

From this point, it’s key to continue using fly control in your feed until 30 days after the first frost in the fall. Continuing treatment in the fall is just as important as starting early in the spring. 

Proactive treatment later in the year will help control the next year’s fly population by preventing horn fly larvae from hibernating and surviving the winter (also known as overwintering) below manure pattie before later developing into adult flies.

Feed Additives to Consider for Fly Control

There are two main types of fly control feed additives: 

  1. Insect growth regulators (IGR) 

  2. Larvicide products

Both are particularly effective in controlling face and horn flies. If you are considering using either type of additive, check to ensure that these products are also labeled as effective against stable flies and house flies.

Insect Growth Regulators

Insect growth regulator (IGR) products with the active ingredient methoprene are fly control feed additives that deal specifically with horn flies. When fed to cattle, IGR products can disrupt horn fly larvae from developing in the manure of the treated animal. There is no risk to the animal because the IGR isn’t actually absorbed but instead passes through the animal’s manure. 

By stopping the pests from developing into biting adult flies, you’ll prevent a potentially expensive impact on your herd. Luckily, methoprene is a very cost-effective fly control approach. It costs as little as 2 to 4 cents per animal per day.

ClariFly® Larvicide Premix 0.67% is an effective IGR and is available on the FBN animal health store


Larvicide products with the active ingredient diflubenzuron are another popular feed additive form of fly control.

Diflubenzuron works by interrupting a fly’s life cycle instead of killing it outright. It targets a fly’s ability to develop an exoskeleton, which means it’s not able to survive into adulthood. 

Consider adding a larvicide like Rabon™ Oral Larvicide to your animal’s feed as a cost-effective way to control flies without a lot of additional work or effort.

Is Garlic Effective? 

Some farmers have found success by adding garlic to their loose mineral or tubs to help repel flies. While research on this strategy is still being developed, early results look promising. 

Shop loose mineral and lick tubs on FBN.

Unlike IGR or larvicide, garlic does not prevent or kill flies; instead, it functions as a natural repellent. As with all fly control programs, it’s best to use garlic in conjunction with other fly control measures such as fly tags and pour-on insecticides.

Get the Fly Control Products You Need to Be Proactive

By cleaning the areas where your animals feed and congregate, as well as where flies breed, you’ll be able to better control and proactively address flies before they negatively impact your herd this season. 

When budgeting for your fly control program, plan to proactively spend most of your budget in April, May, and June.

Find a diverse selection of fly control products through FBN, including:

When you are proactive with your fly control program by shopping on the FBN Animal Health Store, you can unlock exclusive discounts, get price transparency, make your order from anywhere and at any time, and schedule delivery directly to your farm.

Related Resources

Works Cited

  1. https://extension.sdstate.edu/fly-control-considerations-cattle-pasture

  2. https://beef.unl.edu/cattleproduction/controllingflies

The above is provided for information purposes only and should not be used for the diagnosis or treatment of any condition. This information does not cover all possible variables, conditions, reactions, or risks relating to any topic, medication, or product and should not be considered complete. Certain products or medications may have risks and you should always consult your local veterinarian concerning the treatment of your animals.

© 2014 - 2024 Farmer's Business Network, Inc. All rights Reserved. The sprout logo, “Farmers Business Network”, “FBN”, "Farmers First" and “FBN Direct” are trademarks or registered trademarks of Farmer's Business Network, Inc. ClariFly® is a registered trademark of Wellmark International, Rabon™ Oral Larvicide is a trademark of Elanco US, Inc., QuickBayt® is a registered trademark of Bayer Healthcare, LLC Animal Division. 

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FBN Network

Apr 10, 2024

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