The Influence of Penicillin in the Diet of White Leghorn Hens upon Production and Shell Quality of Eggs

AN EXCELLENT and thorough review of antibiotic influence upon egg production has recently been presented by Branion et al. (1956). Additional review herein is limited to antibiotic investigations concerned with calcium utilization and egg shell quality. Migcovsky et al. (1951), using radioactive calcium, reported that penicillin increased calcium deposition in the tibia. Lindblad et al. (1952) obtained results indicating that aureomycin improved the utilization of calcium and phosphorus. Ross and Yacowitz (1954) reported significant increases in bone calcification of chicks fed 2.5 grams penicillin per ton of feed. Increased plasma calcium in male chicks was reported by Bogdoroff and Shaffner (1954) when penicillin was fed. These workers also obtained improvement in shell quality of eggs from yearling hens during July and August as measured by specific gravity. No improvement resulted when penicillin was fed to pullets during September to November. Gabuten and Shaffner (1954) conducted 2 experiments of relatively short . . .