Keeping dairy cow parasites at bay

External parasites such as ticks, mites, lice, and horn flies invariably accompany grazing ruminants. Whether they do little damage or cause substantial losses in production is determined by how the animals and the pasture they graze are managed. If grazing animals are to perform well, the burden of external parasites should be kept to a minimum. Studies have shown that infestation with external parasites may cause irritation, biting, and scratching of large areas of the skin, and infested a