THE PEST PROBLEM

Horn flies, stable flies, and face flies cost the cattle industry an estimated $1 billion+ annually in the United States. This is due to skin irritation, blood loss, decreased grazing efficiency, reduced weight gains and decreased milk production. When flies are left uncontrolled, calf weaning weights have been shown to be 10-20 pounds lighter than when managed.

INSECTICIDE OPTIONS

There are several insecticide options that aid in the control of these pests. These include dust bags, backrubbers, feed additives, sprays, pour-ons and insecticidal ear tags. Each of these has their own advantages and disadvantages. Dust bags and backrubbers are great in a forced-use situation, where animals must pass through that area in their daily lives, though there is a time cost in checking and repairing bags.
Oral larvicides and insect growth regulators are feed additives that pass through the animal’s digestive system and prevent larvae from developing in the manure. These are fantastic for larvae control, although they only go so far with controlling adult flies that travel between herds.

INSECTICIDAL EAR TAGS

Insecticide ear tags are ear tags that have been “infused” with – you guessed it – insecticide. This insecticide is spread on the animal via grooming or rubbing, allowing it to do it’s work. As you may suspect, these ear tags are especially effective around the ears and face.

The best way to maximize the efficiency of insecticide ear tags is through rotation. Different tags have different active ingredients, and rotating your tags helps to minimize the resistance that flies develop to the insecticide. For example, over 4 years’ time, you may use a Synergized Pyrethroid & Macrocyclic Lactone tag for year 1, an Organophosphate tag for year 2, a different Pyrethroid tag for year 3, and another Macrocyclic Lactone tag for year 4. Lather, rinse, repeat.

It is best to tag animals as late as possible to maximize efficiency when flies are most active. Nursing calves are mostly left alone, so focus your efforts on mature cows and weaned calves. Be sure to remove tags at the end of the season to minimize insect resistance.

Considering the fact that these tags work by rubbing off on the animal, it is of the utmost importance that you wear non-permeable gloves when tagging. It is also important that you wash your hands thoroughly after use. Always read and follow label directions for safe use of any and all pesticides!

THE BEST SOLUTION

When you consider the pros and cons of each insecticide option for controlling flies, it becomes clear that the best solution is to utilize a combination of methods. Ear tags are great for the face and head, sprays and pour-ons are great for the back, belly and legs. Feed additives are fantastic larvae control, and dust bags and backrubbers are effective in forced-use areas.