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Garlic: Another option to combat flies


It seems that we are hearing more about the practice of using garlic as a feed supplement for livestock to reduce the negative impact of fly populations. The practice of feeding garlic or garlic-derived compounds isn’t new, but more supporting evidence and research into the benefits is starting to appear.

Garlic, other than being a popular spice, has been used for its so-called medicinal properties by humans since ancient times. Garlic does have some antimicrobial, antioxidant and anti-hypertensive properties and has also been shown to have anti-parasitic properties in sheep and goats, among other species. Other benefits of and claims about feeding garlic include improved animal performance and feed efficiency and reduced methane production.

Research supporting garlic’s effectiveness at repelling flies and reducing the impact of biting flies is varied and limited; however, one study with grazing cows in Canada found a reduction of fly counts by over 50% on cows that were supplemented with garlic powder added to salt, as compared to control groups without garlic (Durunna & Lardner, 2021). This seems to be the most valid trial to date and is often referenced in much of the popular press around the topic of supplementing garlic to cattle. 

So how does this all work?

Garlic contains the compound alliin, and when crushed or ground, alliin is converted to allicin, which then breaks down into various sulfide compounds. When garlic is consumed, these sulfur compounds circulating in the bloodstream are released via the skin and lungs. These compounds can have a repellent effect on insects, thereby serving as a deterrent for flies bothering cattle. Note that we refer to this mode of action as a fly repellent as opposed to total control of the population or life cycle of flies, which can be achieved through insecticides, insect growth regulators, etc.

What CRYSTALYX® product options with garlic are available?

Our first CRYSTALYX product with garlic, Mineral-lyx® GFC, was developed for the Canadian market in 2018. A very similar formulation was then introduced to the U.S. market about a year later, where it is known as Mineral-lyx® GFR. This year, since our Blueprint® line has become very popular, we’ve added to two different CRYSTALYX Blueprint formulations to our offerings: Blueprint® 6% Phos GFR, a mineral product, and Blueprint® 20 AN GFR, a protein supplement.

The cost of the CRYSTALYX GFR products mentioned above is very similar to the cost of feed-through insecticide programs utilizing ClariFly®, Altosid® or Rabon®. It is important to note, however, that the nutrient fortification and feeding levels of various fly control supplements will vary and, as a result, will make the cost per barrel or pound different for each supplement. Always compare the feeding rates and cost per head per day to better understand the real cost of the product.   

Is all garlic the same?

The simple answer to this question is no. There are different varieties of garlic originating across the globe, as well as different processing methods that can lead to varying levels of sulfur compounds that eventually end up in the product. This variability affects the stability of allicin and the allyl sulfide compounds, as well as the granular size and consistency. Additionally, with many garlic powders, the exact level of garlic included is not well-defined.    

Our CRYSTALYX GFR products include a more standardized product called Garlium®, which includes a garlic oil that’s very stable and has a high concentration of allyl sulfides. This is important for the efficacy and performance of the product.

Is feeding garlic becoming a more popular concept?

There’s not much that’s new about the practice of using alternatives to medicated feeds or feed-through fly-control compounds. Over the years, many additives have come and gone — and some gained traction and have great merit. The Veterinary Feed Directive that became law in 2017 has, perhaps, driven the desire for “natural” alternatives and the interest in becoming more innovative. There are also more producers involved in value-added marketing programs that may restrict the use of certain feed additives, ingredients or practices. 

Thinking back over my career in the feed industry, there have been many supplements and feeding practices brought to the market that were met with great skepticism. I think this is true of any new innovative practice. We will likely learn more about the feeding of garlic and other essential oils and the benefits of doing so in the years to come. CRYSTALYX has always been an attractive delivery vehicle for supplying these types of additives because of its predictable and consistent intake. 

Management still counts

When implementing an effective fly-control strategy, consider taking an integrated approach. Start using CRYSTALYX feed-through fly-control products or GFR products at the right time of year. Feed your supplements continuously and at the right levels, and remember: no fly-control program is 100% effective. Additional methods of control — such as applying adulticides or sprays, etc. — can help, too.

For more information on all of the seasonal fly-control products CRYSTALYX offers, contact your nearest dealer.



Durunna, O., & Lardner, H. (2021). Impact of Garlic-Infused Salt Supplement on Fly Abundance, Salt Intake, and Defensive Behaviors in Grazing Beef Cows. Sustainable Agriculture Research; Vol. 10, No. 1; 2021. URL : https//doi.org/10.5539/sar.v10n1p54