Protein, methionine, lysine and a fermentation residue as variables in diets of young turkeys

A study was conducted to determine the effects of adding methionine, lysine and a fermentation residue to practical-type diets containing 24, 27, and 30% protein for young turkeys. A 2 X 2 X 2 X 3 factorial design of variables was used in each of two seven-week experiments. A total of 864 poults were divided into groups such that the 24 diets were each fed to 9 males and 9 females in each experiment. Seven-week body weights were increased 11.4% from 0.1% added DL-methionine and decreased 13.7% from 1.5% added fermentation residue, L-Lysine added at 0.157% failed to increase significantly body weights. Increasing the protein from 24 to 27 and 30% increased seven-week body weights 16.7 and 28.9%, respectively. As dietary protein increased, the increases in body weight from added methionine became smaller, i.e., 16.9, 14.4 and 4.8% in diets containing 24, 27, and 30% protein, respectively. Plots of body weight on (1) amount of methionine and on (2) amount of total sulfur amino acids in the diet show a closer relationship with the latter. The sulfur amino acid requirement of poults to seven weeks of age appears to be at least 1.03%, the highest quantity used in this study. The fermentation residue, a product not currently marketed, remains after the isolation of spectinomycin from controlled fermentation of Streptomyces flavopersicus and contains 14% dry matter. The cause of the depressed growth from the added fermentation residue has been discussed.