Cattle Ear Tags

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Horn flies are considered the most important external parasite of cattle. With high summertime populations, they cause cattle to lose weight and lower milk production. Oklahoma State University has a horn fly project that is conducted on an annual basis to see how different insecticidal ear tags perform from year to year.

Recommendations from their project include:

• Begin horn fly control procedures in the spring when cattle average approximately 200 horn flies.
• If ear tags are used, the insecticide classes must be rotated. Do not use a pyrethroid ear tag more than once every three years. Do not use an organophosphate ear tag more than two years in succession. Continuous use of ear tags in the same insecticide class will eventually result in horn fly resistance.
• Remove ear tags at the end of the fly season or when they lose their effectiveness. Do not tag cattle more than once per fly season, regardless of insecticide class.
• If additional horn fly control is needed later in the year, use sprays, pour-ons, dusts or backrubbers. If possible, alternate insecticide classes when changing control methods.
• If pyrethroid ear tags have failed to control horn flies in the previous year, pyrethroid insecticides in any form should not be used for at least two years. In the meantime, use non-pyrethroid ear tags, sprays, pour-ons, etc.
• What animals should receive tags? YES: Heifers, Cows and Weaned Calves NO : Bulls and Calves still on their mother