Dietary protein and yolk sac inoculation with Escherichia coli in young turkeys

An experiment was conducted to examine the effect of pathogenic Escherichia coli inoculated into the yolk sac of day-old turkeys. Escherichia coli was isolated from the yolk sac of stunted poults and inoculated directly into the yolk sac of day-old birds. Poults were administered either .1 ml of uninoculated sterile Todd-Hewitt broth or .1 ml of a 10(-3) or 10(-2) dilution of a 24-hr E. coli culture containing 3.4 X 10(8) viable bacteria/ml. In addition, poults were fed either 28 or 22% protein diets from 0 to 21 days of age to form a 3 X 2 factorial arrangement. Body weight gain and feed consumption were measured weekly, and dry matter and protein retention and nitrogen-corrected metabolizable energy were measured from 7 to 10 and 17 to 20 days postinoculation. Intestinal mucosal dipeptidase and maltase activities were determined at 21 days of age. Average mortality by 7 days of age was increased from 1 to 36% from the E. coli inoculation of the yolk sac. Escherichia coli significantly depressed body weight gain and feed consumption 27 and 30, 13 and 16, and 6 and 8%, respectively, during the first, second, and third weeks of the experiment but failed to affect feed efficiency. Feeding a 28% protein diet alleviated the depression in feed consumption and body weight gain to some extent compared with a substantial depression at 22% protein. Nitrogen content and gross energy of the excreta were increased by both dilutions of E. coli for the 7 to 10-day period; this was indicative of a malabsorption of nutrients.(ABSTRACT TRUNCATED AT 250 WORDS)