Cattle lice (Anoplura, Mallophaga) in New York: seasonal population changes, effects of housing type on infestations of calves, and sampling efficiency.

A year-long survey was made of commercial dairy herds in New York for cattle lice (Anoplura and Mallophaga). All herds were infested with lice. The cattle bitting louse, Bovicola bovis (L.), accounted for about 90% of the observed infestations; infestations of mature animals were most common during the winter months, especially March (26% infested); and infestation rates of calves were high (30-45%) from January through June. Cows that were housed in stanchion barns were about twice as likely to be infested (24.7%) as were those in free stalls (11.1%). Calves housed in individual outdoor hutches had substantially lower infestation rates (4.5%) than calves maintained inside barns in collective stalls and pens (46.0%).