Levels of Antibiotics in the Intestinal Tract of Chicks Fed Bacitracin and Penicillin , ,

Abstract

BARE et al. (1964a) reported that antibiotic assays of the intestinal contents of chicks fed a bacitracin-penicillin mixture, with and without uric acid, showed rapid penicillin inactivation in the tract but persistence of the bacitracin. This report concerns the levels of antibiotics in the intestinal tract of chicks fed diets containing bacitracin and penicillin alone and in combination. EXPERIMENTALDay-old male chicks (Vantress×Arbor Acre) received from a local hatchery were distributed randomly into groups of 40 chicks each. Each chick was wing-banded and weighed at weekly intervals. The chicks were maintained on raised wire-mesh floors in an electrically heated battery in a continuously illuminated room which had been used previously to house chicks. Diet and water were supplied ad libitum. The chicks were fed the following diets: a glucose-fat-soybean meal diet (Bare et al., 1964a), hereafter referred to as the basal diet; the basal diet plus 11 mg./kg. of zinc…