Effect of Penicillin on the Growth of Turkeys Fed Diets of Varying Protein Content

IN EXPERIMENTS made by Slinger et al. (1951) and McConachie et al. (1952) penicillin did not appear to alter the protein requirement of chickens for growth or reproduction. In the case of growing chicks the antibiotic was found to enhance protein utilization and to increase the tolerance to high levels of protein. In this work energy utilization was also improved thus obviating reduction in the effective level of protein. Evidence obtained by Machlin et al. (1951) suggested that aureomycin may reduce the protein requirement of growing chicks. Similarly, McGinnis (1951) reported that a diet containing approximately 24 percent protein and penicillin gave growth in turkey poults at 4 weeks of age comparable to that obtained with protein levels as high as 28 percent. This author also found that a diet containing 22 percent protein and terramycin did not promote growth of turkeys at 8 weeks of age as effectively as . . .