STUDIES of the effect of growth-promoting levels of antibiotics in the ration of laying chickens on their egg production have resulted in conflicting results. The latest reports available to us on this subject are those of Brown et al. (1953), Elam and coworkers (1953), and Lillie and Sizemore (1954); and these authors have adequately reviewed the literature on investigations preceding theirs.
... [Show full abstract] One possible explanation for the disagreement between the data of different experiments might be in the results of Lillie and Sizemore (1954), who found that antibiotics “definitely improved egg production of the low producers, but not that of the high producers.” With regard to high-level antibiotic feeding Balloun (1954) found “that under conditions unfavorable to high egg production, the addition of antibiotics at a high level may improve egg production.” A similar thought is expressed by Couch (1954).
The injection of high, therapeutic doses of antibiotics is recommended in …