Controlling lice in cattle

Source: Lee Townsend, UK Extension entomologist

During the cold winter months, lice numbers increase. They can spread from one animal to the rest of the cattle herd as the animal’s bunch together. In time, the whole herd may become infested but usually only a few animals become extremely lousy. Infested animals rub and scratch excessively in response to the irritation caused by lice.

Biting and sucking lice can cause slow weight gain or even a gradual loss, louse-induced anemia, or lowered resistance to stresses, such as cold, wet weather. A carefully planned and timely louse control program will cut losses greatly.

Both biting and sucking lice can occur in a herd. Typically, only a small number of animals are heavily infested. A few lice survive the hot summer months on “carrier” animals, usually bulls or old cows.

The bull’s longer, denser coat and heavier neck and shoulders prevent him from grooming efficiently. Self-grooming helps to reduce louse numbers. Nutrition, general health, and reduced effectiveness of the immune system of older cows can predispose them to louse infestations.

Confirm a suspected louse infestation by a careful examination of the most agitated animals. Part the hair at points along the neck, head and around the eyes, on the withers, brisket, and shoulders to look for nits (eggs) and lice. Sucking lice can occur in patches. They have narrow, pointed heads and tend to remain attached to the animal. Chewing lice are more active and have a wider, triangular head.

There are several control options for lice but the list of options narrows, especially at this time of year. We are beyond the treatment date for cattle grubs, so a systemic insecticide should not be used unless a grub treatment was applied earlier.

A whole animal spray gives the good coverage needed for effective louse control and is also one of the cheapest treatments. This leaves pour-ons and dusts as relatively “dry” alternatives.

Check the label carefully before you buy. For example, you may find different costs for products containing the same concentration of a specific active ingredient. Also, look at the application rate and method. Some products have an applicator or measuring device to help deliver accurate doses. This is very helpful when dose rates are just a few cc’s per head.

Note other cautions or restrictions on the label. Especially important are the time to wait between applications (two are needed for louse control because the egg or nit stage is not killed) and protective equipment to be used during application.

For more information contact the Clinton County Cooperative Extension Service at 606-387-5404.

Educational programs of the Kentucky Cooperative Extension Service serve all people regardless of race, color, age, sex, religion, disability or national origin.

Commercial Poulgtry Grower

Program

The Clinton County Extension Service and Kentucky Poultry Federation are hosting a poultry growers meeting on December 9th at the Clinton County Fairgrounds starting at 10:00 am CST.

Several vendors will be on hand to talk with growers about services and products they offer to the poultry industry. The speakers for the meeting will include UK specialist Doug Overhults, LEI –Products President Scott Laskowski, Lubing USA area rep. Barry Dutton, and GOAP area contact Bill McCloskey.

Information will be presented on poultry house lighting and energy savings, biomass/wood heating systems, energy grants, and drinker line management. A meal will be served following the presentations.