Limiting Essential Amino Acids in Soybean Meal for Growing Chickens and the Effects of Heat Upon Availability of the Essential Amino Acids

THE seriously limiting essential amino acids in a feedstuff can generally be identified by comparing the feedstuff's chemically determined amino acid content with the amino acid pattern needed to produce rapid growth. It is sometimes difficult to identify marginally deficient amino acids by this method, however. The availability of individual amino acids is affected to different degrees by the processes used in producing a feedstuff; this also makes it more difficult to identify the limiting amino acids. For these reasons chick tests are being conducted at this station to determine which amino acids are most limiting in the protein of several commonly used poultry feedstuffs. Two previous papers have reported results of experiments conducted with peanut and cottonseed meals (Anderson and Warnick, 1965, 1966). In the experiments with peanut and cottonseed meals, the rations contained 18 percent protein from the feedstuff studied and a mixture of the amino acids thought . . .