Abstract
1. Reactivity of polyclonal rabbit CD3 antiserum to human T cells and density of CD3 cells in chicken intestine were studied after the inoculation of 1‐d‐old broilers with intestinal homogenate to develop the Runting and Stunting Syndrome. 2. Reactivity of CD3 antiserum in chicken intestine was very good. 3. Increased numbers of epithelial lymphocytes as well as infiltration of CD3 cells into the lamina propria were demonstrated. 4. Intestinal homogenate caused impaired growth and bad feathering in broiler chickens until 21 d of age.