When cattle start rubbing and losing hair in late winter or early spring, lice are often the first suspect. Follow-up checks by producers and veterinarians, however, show the cause is not always that simple.

The winter months and routinely low air temperatures present unique challenges for feedlot cattle, particularly in terms of maintaining health and productivity. Cold temperatures, fluctuating weather conditions and increased feed requirements can induce stress in cattle and result in health complications.

In order to have healthy animals, producers must understand the normal health attributes of livestock, routinely monitor their animals and make management changes when necessary.

Five species of lice parasitize cattle in the U.S. Four of these are blood feeders, and the fifth is a biting or chewing louse. Cattle with hair loss, an unthrifty appearance, and leaving hair on fences and other objects from rubbing may be a sign of lice infestation.

While most ectoparasites may take a break for the winter, it is important not to let your guard down because some parasites like mites and lice prefer the cooler time of the year.

What are cows doing if parasites are hanging around? Certainly not what they’re supposed to be doing. External parasites can affect a cow’s milk production immediately, because cows will spend their time scratching instead of eating or resting.