Amino Acid Requirements for Maintenance in the Adult Rooster

Abstract

The maintenance requirements for tryptophan, phenylalanine, methionine, cystine and tyrosine were computed from nitrogen balance studies in adult roosters not depleted of protein. A diet supplying the determined maintenance requirements maintained the birds in positive nitrogen balance. Using a histidine-free diet which maintained positive nitrogen balance no changes in hematocrit levels were noted, but breast muscle concentration of anserine and carnosine decreased compared with control birds fed a histidine-containing ration. A significant correlation was found to exist between the maintenance requirements and the amino acid content of feather protein.