A sampling of factors relative to the epidemiology of gastrointestinal nematode parasites of cattle in the United States.

摘要: Gastrointestinal nematodosis of cattle is a parasitic condition resulting from an immense and seemingly forever-expanding array factors. Countless determinants influence the incidence severity species-specific infections that occur in cattle, affect free-living or environmental stages parasites stages. The vast majority animals have subclinical economic level parasitism undetectable to eye but quantified more accurately by treatment-induced improved performance (e.g., feed efficiency, nitrogen balance, weight gain, milk production). Unfortunately, results treatment (effectiveness animal performance) sometimes can be as varied parasitisms are being treated.