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Your Blueprint® for Fly Control

February 18, the day I saw the first few flies on the set of sale heifers we are getting ready for this spring. Man, I feel like I start seeing these nuisances earlier and earlier each year. I think we all have seen the astonishing numbers on the economic impact that flies have on our industry. Losses from just horn flies are estimated at $1 billion each year due to the stress they inflict and the cattle disease they spread.

Because of these numbers, the production livestock industry has developed a huge portfolio of tools a producer can use to combat flies. The popular options available are ear tags, pour-ons and sprays, back rubbers and dust bags, and feed-throughs. Feed-throughs will utilize some form of larvicide affecting the larvae in the manure of the treated animals; the other options contain adulticides that affects adult flies. Due to these products affecting flies at different stages of their life cycles, it might be beneficial to utilize multiple methods in your strategy.  

I always say that the silver bullet has not been created yet, so deciding which type of solutions work best is unique to each operation. Producers need to understand their current situation to get the results they are after.

Ear tags

Pesticide ear tags are a popular option for many cattle. There are multiple brands and chemical combinations to choose from. Most producers will put in these tags when working cattle for spring vaccinations/branding. When using ear tags for fly control, it’s important to rotate the active ingredient to limit insect resistance.

Pour-ons and sprays

The quick hitters of the options. You can see an immediate effect, but the control only lasts for a short time (1–21 days). Sprays are typically applied to the whole animal and must be used more frequently than pour-ons, requiring a producer to have easy access to the animals. Pour-ons are typically applied down the animal’s back and last a touch longer, but multiple reapplications will be required throughout the fly season. For easy application, cattle will need to be brought into the pens.

Back rubbers and dust bags

Back rubbers and dust bags are treated with pesticide chemicals and are applied when cattle physically brush against the applicator. In pastures where cattle must travel through a gate/gap to get to water/feed/hay, these are awesome tools. In larger pastures, where consistent visits to the applicator cannot be assured, back rubbers and dust bags are less effective.


Feed-through fly control uses an insect-growth regulator (IGR) to treat the manure and prevent new flies from emerging. The two types of IGRs we use in our formulas are ClariFly® (for horn, house, face and stable flies) or Altosid® (for horn flies only).

Feed-through is one of the most popular options producers incorporate into their fly control programs. Why? Because it allows them to “double dip,” getting the benefits of additional supplements along with the benefits of fly control.

You can find some blended or pelleted feeds with feed-through fly control, but the most common option is through a self-fed supplement, such as a Crystalyx® low-moisture block (LMB), or in the form of loose mineral, as our sister company Sweetlix® offers. Loose mineral delivery for IGRs has continued to grow in popularity over the years. Having the supplement out constantly in front of the cattle in smaller groups or larger pasture situations is a big help. Plus, in situations where you would like higher phosphorus levels, you have a touch more formula flexibility.

However, an IGR only works if it is consumed and passes through the digestive tract — and loose mineral consumption can be lower. Research out of Montana State University tracked the percentage of cows consuming a loose mineral supplement versus cows consuming Crystalyx. Results showed that whether cattle are in a grazing scenario or being fed hay, 86% or more will consume a Crystalyx mineral supplement, compared to 55–63% consuming a loose mineral.

(Rangeland Ecology & Management 60(1), January 2007).

That’s why the consistent delivery of Crystalyx makes it a great option when delivering fly control to a cow herd. Not to mention the added benefits that come from the supplement it’s delivered in.

All our fly control technologies contain a partial inclusion of organic trace minerals if you’ve followed our blog series, you know that our Blueprint® solutions, like Crystalyx Blueprint 6% Phos with ClariFly and Blueprint 20AN with ClariFly, contain 100% organic trace minerals. The benefits that come with switching entirely to these superior mineral forms, a switch that Alltech calls Total Replacement Technology (TRT), are unmatched.

Flies are here to stay, and with the negative economic impact that comes from the stress they bring and the disease they spread, we must plan ways to control them. Hopefully, this blog has started the Blueprint® for you to plan your attack on the fly battle this upcoming year.