Lice infestation is a common problem of cattle during the cold weather months. Hair loss and patches of raw skin are indicators. Whether the infestation is from biting lice or sucking lice, cattle can become unthrifty, have reduced weight gains, and lose weight. Hair loss as a result of lice can also make cattle susceptible to frostbite. Most authorities make recommendations on treating and controlling lice, but it is wiser to manage for herd health, not against lice.
Biting lice and sucking lice both tend to stay on the host animal but are also transmitted from animal to animal by direct contact. Management to aid in keeping infected and non-infected separate should include:
Avoid crowded situations, such as hay rings and bunched feeding.
Avoid bunching cattle in barns during fall and winter.
Sync calving with nature to reduce/eliminate need for hay and supplemental feed. Cows that calve in sync with nature are in their first or second trimester of gestation during winter months and have a lower energy requirement than cows in their third trimester and cows with new calves at side.
It is hard to mechanically get rid of lice because they have legs that can grasp onto cattle hair very well, and they produce nits (eggs) that are glued to the hairs. Management to aid in removal of hair coats that harbor lice include:
Select cattle that shed early in spring. Direct sunlight and short haircoats keep populations low.
Short haircoats also allow removal of lice while self-grooming.
Unthriftiness as a result of malnutrition, low dietary energy, cold stress, shipping stress, handling stress, concurrent infection, or internal parasites make cattle are more susceptible to lice. Unthriftiness leads to weight loss and compromised immune defenses. Management to aid in maintaining efficient cattle include:
Maintain body condition score (BCS) through proper grazing.
Calve in-sync with nature to match nutrition needs with available forages.
Select moderate-framed cattle that have a lower energy requirement and more easily maintain their BCS.
Practice low-stress handling to facilitate the animal’s health and well-being.
Don’t base your grazing program on monoculture pastures. Plants in diversity utilize soil nutrients, water, and energy from sunlight more effectively than do single-species or few species grazing lands. Those plants can then better supply all the nutritional needs of the cattle.
If a bull or cow/heifer is new to the herd, you may want to segregate and treat that individual. It is usually best to cull unthrifty bulls and cows, and not keep their offspring. In some situations, any bull and cow may become infested and spread lice. If the animal is otherwise thrifty and in good health, early hair shed and direct sunlight should suffice for recovery.
Early breeding seasons facilitate passing lice from cow to bull to cow, and from cow to cow. Early breeding seasons—which produce calves born in winter months—occur before hair is fully shed and exposure of lice to direct sunlight can occur. When bulls mount cows or cows ride other cows in heat, the chances of passing lice from an infested animal to a non-infested animal increase. Management to aid in keeping non-infested animals lice-free during breeding season include:
Calve in-sync with nature.
Select cattle that shed early in spring.
Genetics play an important role in lice-free cattle. Management to aid in producing cattle that do not succumb to lice include:
Select animals that are moderate-framed.
Select animals that “slick-off” early.
Select animals that maintain a good BCS.
Select animals who have not and whose parents have not been infested with lice.
Aside from the financial aspects of raising cattle, the foundation for success is found in soil and pasture health, low-stress handling, and genetics.