T h e Effect of Antibiotics on the Growth of Two Varieties

McGINNIS a al. (1949) reported a growth promoting effect of a fer-mentation supplement for turkey poults under conditions where materials con-taining vitamin B12 failed to produce a response. This supplement was later found to contain aureomycin. Stokstad and Jukes (1950) stated that a purified prepa-ration of aureomycin promoted growth of chicks and turkey poults comparable to that obtained with dried aureomycin fermentation mash. Almquist and Merritt (1951) confirmed and extended the work-of Stokstad and Jukes by obtaining simi-lar results using a different basal ration on a different variety of poults. McGinnis el al. (1951) reported that aureomycin, streptomycin, terramycin, and penicillin stimulated the growth rate of turkey poults. In a comparison of the effects of aureomycin, streptomycin, terramycin, and penicillin, McGinnis el al. (1951) re-ported that penicillin was the most ef-fective and streptomycin was the least effective of the antibiotics used. Com-binations of other antibiotics with peni-cillin gave no greater growth response than penicillin alone. Leucke et al. (1950) found streptomycin effective in promoting the growth of pigs. Tests were conducted at this station Published with the approval of the Director of th