Control Winter Pests of Cattle: Lice

Weekly Newspaper Article for The News-Democrat, Carrollton, KY

(Montana State University Extension)

It has been a cold start to the week and making sure our livestock are adequately cared for in these cold temperatures is a concern for all livestock producers.

In addition to being mindful of feeding high quality forages and supplemental grain to provide energy and keeping waterers flowing, we should also take a look at another pest of winter:  lice.

Lice are cold-loving pests that can spread when animals bunch together in response to frigid temperatures.

Reduce potential lice problems on cattle by keeping new animals separate from our herd until you have given them a thorough louse treatment, generally two applications of a contact insecticide.



The first application kills active adults and immature lice, but it will not destroy nits on the hide.  A second application targets new hatchlings from the nits and any other lice still around.

Be sure to follow the label instructions on treatment intervals.  After these two treatments, you can add new animals to the herd with minimal chance of lice problems during the winter.

Do not use systemic insecticides during the winter unless you know the treatment history of newly bought cattle.  This is because migrating grubs might be in sensitive locations and cause an adverse reaction this time of year.

Winter also is a good time to reduce future weevil problems in alfalfa by letting beef or dairy cattle graze dormant fields.  Alfalfa weevils lay a significant number of their eggs in living and dead stems.

Winter grazing helps manage alfalfa weevils in two ways:  grazing removes stems holding deposits of weevil eggs, and it removes stems that can serve as sites for females to lay the remaining eggs in the spring.

Letting your cattle graze alfalfa fields in the winter can reduce weevil populations substantially, possibly to the level that you will not need a spring insecticide application.