Cattle Fly Control

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Spring is here! We are finally starting to see some warm weather, sunshine, and green pastures. Spring and summer are my most favorite times of the year, even if they do bring pests, like flies. Flies love the farm and your cattle. Get a jump-start on controlling your fly population NOW!

Face flies feed on the nasal and eye secretions, hence their name. They can cause cattle to lose weight and increase the risk for pink-eye. If pink-eye is left untreated, it can lead to blindness. Face flies lay their eggs on fresh cattle manure and larvae develop in the manure and soil in about 2 – 3 weeks. Face flies typically move from animal to animal and don’t spend much time on one animal.

Horn flies are probably one of the more common flies and one of the biggest economic pests. Horn flies are biting flies and feed on the blood of cattle. Five hundred horn flies can remove one pint of blood each day from a cow. Horn flies are usually found on the shoulders, down the backs, and on the tail head of cattle. Horn flies remain on the cattle at all times, unlike the face flies that move from animal to animal.

Stable flies also are blood feeders but feed much like face flies. Stable flies usually lay their eggs in decomposing, wet straw and can be found around hay bales. Stable flies like to feed on the legs and back of cattle.

Controlling flies is important. Failure to do so can reduce performance and money. Every $1 spent on fly control gives the producer a return of $5-$10. There are a number of options that can be implemented. Each operation may differ depending on the number of animals and resources.

Producers can use insecticides that can be fed to the animal; mineral supplement is usually the more common route. Cattle eat the mineral supplement, and then it is excreted in the manure. The flies lay eggs in the manure and the insecticide in the manure stops the fly larvae from developing into adult flies. Insecticides do not work on adult flies that are already present on the farm. Other control methods include insecticide ear tags, back rubs, sprays, dusts, and pour-ons. Insecticide ear tags or fly tags work to kill flies that are present on the animal. They should not be applied until 200 or more flies are present, and it is important to remove the fly tag in the fall to prevent flies from becoming resistant. Back rubs also provide effective control. It is important that they be recharged every week or so. Back rubs should be placed near water or minerals so cattle have to walk under them. Sprays, dusts, and pour-ons are also good means to control fly populations. The biggest issue with using these methods is that it can become labor intensive and will need to be reapplied every 2 – 3 weeks.

For more information, please contact Taylor Chavis, Extension Livestock Agent, at 910-671-3276, by E-mail at Taylor_Chavis@ncsu.edu, or visit our website.

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