Amino Acid Deficiencies in Peanut Meal and in Corn and Peanut Meal Rations

GRAU (1946) fed chicks rations containing 20 percent peanut meal protein and several different mixtures of the amino acids lysine, methionine, tryptophan, and threonine. Growth rate was decreased the most when methionine was omitted from the amino acid mixture. A smaller but significant decrease was noted when lysine was omitted. Omission of threonine or tryptophan did not produce a significant reduction in growth rate. It was concluded that peanut meal is lacking primarily in methionine, but is also slightly deficient in lysine. The levels of the essential amino acids in a ration with 18 percent peanut meal protein were compared to the levels that a series of experiments conducted in our laboratory (Dobson et al., 1964) had indicated were well balanced. It was predicted on the basis of the comparison that a ration containing 18 percent peanut meal protein would be deficient in threonine as well as being deficient in…