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Maximizing Cattle Ear Tags For Fly Control

published: April 15th 2011
by: Brandon Sears
source: The Richmond Register

RICHMOND — Insecticide impregnated cattle ear tags have been a popular means of pasture fly (horn fly and face fly) control for over 20 years. The insecticide in them is transferred to the animal’s hair coat as it grooms and rubs. Insecticide protection lasts for 12 to 16 weeks and the fly control program travels with the animal as it goes from pasture to pasture. Rotation of insecticides from year to year is recommended to reduce the chance of a problem with insecticide resistance, especially in horn fly populations. This shows up in the form of a shorter than normal period of fly control.

Changing tag brands is not enough; insecticides used in a rotation strategy must have a different mode of action (active ingredient) than the previous product used. Tags containing insecticides representing 4 different modes of action are available now and there are some combination tags that contain 2 different types in the same product.

However, reduced fly control can be caused by several different factors.

Some examples: 1) Tagging too early. The 12- to 16-week “fly control clock” starts when tags are inserted. Tagging very early in the spring can mean protection “runs out” before fly season is over. 2) Horn flies moving in from untreated nearby herds can keep pressure high and make control seem less effective. 3) Above normal rainfall can keep manure wetter longer, and more suitable for horn fly breeding than during hot, dry summers when manure dries quickly and may less hospitable for the maggots.

Here are some ways to get the most out of your ear tag-based pasture fly control program in 2011.

1. Rotate insecticide classes annually.

Check the active ingredient in the tag to be sure you know what you are using and record the choice each year. The Insecticide Recommendations for Beef (ENT 11) http://pest.ca.uky.edu/EXT/Recs/ENT11Cattle.pdf, lists the tags by insecticide class. This makes it easier to establish a rotation. If you don’t have Internet access, call our office to have a copy mailed to you, 623-4072.

2. Apply tags after horn fly numbers reach about 100 per side per animal. This will keep them from being applied too early. It takes more than 100 flies per side to have an impact on weight gain.

3. Supplement fly control with dust bags, oilers, sprays, or pour-ons, if needed. Staying on a pro-active program will keep resistance problems at bay.