Sample diets are shown in Tables 2 and 3 for the respective 5-8 and 17-19 wk periods for Treatments 1 through 4. The control diet (Treatment 1) includes animal protein because of its obvious economic advantage and widespread use. Valine content (as a percent of protein) is similar across ingredients; therefore diet protein in these sample diets was fixed by setting a valine specification. Supplemental lysine, methionine, and threonine were used so that all diets contained adequate amounts of these amino acids. For Treatments 5, 6, and 7 supplements of tryptophan, arginine and isoleucine were used.
