Antibiotic Levels in the Digestive Tract of the Chick

SEVERAL investigators have reported that crystalline Chloromycetin is not an effective growth stimulant for poultry. Branion et al. (1951) reported that Chloromycetin was not effective in stimulating the growth of turkey poults. Heuser and Norris (1952) found that Chloromycetin did not stimulate chick growth. In our laboratory, various experiments were conducted in an attempt to learn why crystalline choloromycetin is not active as a growth stimulant for chicks. During the course of this investigation antibiotic levels were determined in the digestive tract of chicks given oral doses of antibiotics. The data on antibiotic levels in the digestive tract may explain the failure to obtain chick growth responses with crystalline Chloromycetin. Leghorn cockerels between four and five weeks of age and averaging 325 gm. were starved for 24 hours but were allowed access to water. Each chick was then given a single gelatin capsule containing 40 mg. of crystalline antibiotic. Preliminary …