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Animal Health Notebook

How to resist big blood-slurping flies

avstraliavasin-iStock-GettyImages Horsefly
Normal methods of control don't work on horseflies, so the author has some alternative advice.
When it comes to horseflies, avoidance is the foundational principle.

There are a lot of cattle in mid-America and the dollars their owners spend on health problems related to flies, ticks, mosquitoes, lice and other external feeders pay bunches of salaries and buy lots of new pickup trucks for folks who live in town.

Previously I discussed horn flies and the control methods that work for us at 499 Ranch. Those programs leave the majority of the production money on our side of the table. Today I’m on horseflies.

All outlaws are bad when their numbers reach excessive levels. Typically, though, it is a matter of a little doesn’t hurt but a lot is bad. Remember that 10% of all populations are outlaws, freaks or dogs. This is normal but the bad guys must be kept in check. There is not enough money to house them all.

When considering most anything that attacks on or thru the skin it is a good idea to first study healthy skin and hair.

Facts about hide

The largest organ is the skin, and it makes up 12-20% of a beef animal’s weight. Further, the skin is reflective of nutritional status, including protein, energy, fat, minerals, trace minerals and vitamins. Soil quality and health is very important.

Skin also is reflective of hormone function and secretion. Cattle that slick off early and have a shiny coat are nearly always more hormonally balanced than those that don’t. Cattle that draw a lot of flies are usually hormonally imbalanced and may be nutritionally deficient, although bulls usually draw more flies than cows. Skin condition is also reflective of genetic quality.

The skin serves many purposes and must function well to do so. One is the production of Vitamin D from sunshine. Another is the complex process of dealing with heat and humidity and insects and other external parasites. Sebaceous gland lipids provide a gloss or sheen to the coat. They are antibacterial, antifungal, hydrating, and anti-parasitic to a great extent. Many secondary and tertiary compounds are included and compounded into the oils that are a part of healthy skin and hair – another reason for the fact that diversity yields stability in the plant community. High-gloss cattle repel flies and other bugs, ringworm and other pathogens.

The hair covering provides a filter, insulator and mechanical protection for the animal. It works really well when all skin functions are highly operational.

Working principles

The reality is that the environment and ecosystems beef producers and/or land managers operate are so highly complicated that we must learn basic principles and then dwell on these principles rather than the details. One of the important concepts is that really good hair and skin is reflective of really good health. And good health is a barrier and repellent to bugs.

Horse flies and deer flies are closely related. Both have razor-like cutting mouth parts. They cut through the skin of their victim and slurp blood and often leave a mess behind them. They are capable of transmitting several protozoa, viruses and bacteria. This includes anaplasmosis and tularemia, as well as Equine Infectious Anemia in horses. The bleeding is done by the females. Also, they do not require manure for their egg-laying but they do like moist and shaded areas.

The good thing about these pests is that they don’t spend a lot of time on the cattle or hatch more than a couple of times annually. They are hard to control by most conventional programs.

Control ideas

Successful management and control of horse and deer flies fits into an old model I’ll call shepherding for the purposes of this blog. Shepherding requires regular presence and cattle movement. It is often feasible to move cattle to water in midday or early afternoon and then later to reduce the closeness to riparian zones. Cattle moved and handled on the ground daily tend to adjust to and enjoy people, which is a plus.

We have been successful giving cattle an extremely small cut of new grass when there is a deer or horsefly hatch. We then feed on a little supplement and we spray a little fly repellent. It will last a day or two or three. We respond to what we see. It doesn’t cost our bottom line much and it works.

Everything I’ve said can be summarized with these four concepts:

  1. Manage/breed for slick, healthy skin and hair. This requires supplement and culling.
  2. Interact with the cattle and become their “buddy” to an extent.
  3. Try to repel pests when they become a problem.
  4. It is hard to manage animal health if you aren’t on the ground with the animals on daily basis.

Paying attention and thinking pays dividends that result in profitability.

The opinions of this author are not necessarily those of Beef Producer or Farm Progress.

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