Extension @ Your Service-Fly Management for Your Livestock

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As warmer weather quickly approaches, so will various insect pests such as mosquitos, ticks and flies. These pests are often a nuisance around the home and on the farm. In the livestock world, effects of fly infestations on animal health and performance are often underestimated. For example, studies have found that high populations of the Horned fly, can reduce cow weights by 30 pounds. Since cattle producers’ paychecks are based on the weight of their calves, this can result is a significant monetary loss if not managed correctly. In the U.S. alone, experts estimate that cattle producers lose almost one billion dollars because of the Horned fly.

In horses, flies are also more than an annoyance. Flies, such as stable flies, can cause horses to constantly scratch which leads to open wounds that can get infected. Certain fly species are also known to transmit diseases such as Equine Infectious Anemia and pinkeye.

To help curve fly populations, here are several things that livestock owners can do:

  • Remove manure, excess feed, and wasted hay.
  • Keep feed storage areas clean.
  • Locate manure sites or compost piles as far from stables/barns as possible, or move them off property. Flies can travel miles to find your livestock.
  • Rotate pastures regularly to let areas dry out.
  • Spread manure with a drag to encourage drying.
  • Release fly predators. These wasps lay their eggs in fly pupae, then kill the developing fly larvae.
  • Feed an insect growth regulator additive, such as Simplifly, to horses.
  • For horses use protection, such as fly masks, sheets, and boots.
  • For cattle, feed mineral with an insect growth regulator additive.
  • There are also insecticide treated ear tags available for cattle.
  • For all livestock there are insecticide sprays (permethrin, pyrethrin) and pour-on treatments available (just a note: overuse of these sprays can cause fly populations to become resistant so use them wisely.)

Managing fly populations can be a difficult task. It is important to remember that there is no “silver bullet” to kill off all the flies on your property. Those livestock owners who are successful at managing fly populations employ several of these practices on their farm. An integrated plan using a variety of these methods is better than any of them alone, especially spraying your livestock with permethrin once a week throughout the summer. If you do choose an insecticide as part of your management plan, it is extremely important that you to read the product’s label before applying it to your animals.

If you have any questions concerning livestock management or insect control on your farm please contact the N.C. Cooperative Extension of Richmond County office for more information.

Anthony Growe

Extension Agent- Agriculture

Row Crops and Livestock