Ag Notes: Cattle lice control
Lice biting and sucking can cause a number of problems in your cattle herd, including slow weight gain or even a gradual loss, anemia, or lower resistance to such stresses as cold, wet weather or disease. To minimize losses, carefully plan lice control programs and execute them in a timely, economical manner.
A few lice can survive the hot summer on a small number of “carrier” animals in the herd, usually bulls or old cows. Lice numbers increase during the fall and winter and spread from carrier animals to the rest of the herd as animals bunch together when the temperature drops. The whole herd can become infested over time, but usually only a few animals become extremely lousy. Infested animals excessively rub and scratch, responding to irritation caused by lice.
Carefully examine the most agitated animals to confirm a suspected infestation. Part the hair at points along the neck, head, around the eyes, on the withers, brisket and shoulders; then look for eggs (nits) and lice.
Mixed infestations of biting and chewing lice can occur in a herd. Biting (sucking) lice have narrow, pointed heads and tend to remain attached to the animal. Chewing lice have a wider, triangular head and are more active.
The following are lice control options effective this time of year:
A systemic insecticide should not be used unless you earlier applied a grub treatment.
A whole animal spray gives good coverage for effective lice control. It also is one of the least expensive treatments.
Pour-ons and dusts are relatively “dry” alternatives.
For an effective, economical treatment you have several factors to consider when making a control choice.
Some products have an applicator or measuring device to help deliver accurate doses. This is very effective when dose rates are a few cc’s per head. Carefully read the label before you buy. For example, you might discover different costs for products that contain the same concentration of a specific active ingredient. Also look at the application rate and method. Note other cautions or restrictions, especially the time to wait between applications. You’ll need two applications for louse control because the egg stage is not killed.
Don’t forget to wear protective equipment during application.
For more information, contact the Boyle County Cooperative Extension Service.
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Jerry Little, County Extension Agent for Agriculture/Natural Resources