An Epidemiologic Method to Determine Losses Associated with Subclinical Gastrointestinal Nematodes in Yearling Cattle

Abstract

In many northern regions of the United States, gastrointestinal nematode infections are largely subclinical, with relatively few cases of clinical disease. At subclinical levels the effects of nematodes are less apparent but lead to decreased rates of production and decreased immunity to various infectious diseases. Subclinical burdens may make it difficult for producers to recognize the loss, and the need to control these parasites. A convenient method to measure subclinical losses under actual herd production conditions is needed to enhance producers' ability to evaluate the cost-benefit of nematode control programs. The objective of this project was to evaluate an epidemiologic-based methodology, which measures losses due to subclinical gastrointestinal nematode infections in yearling cattle on a single pasture.