Reducing dietary CP can reduce N pollution. Much research has been reported in corn-based diets; however, the amino acid (AA) profiles of wheat-based diets differ. Poor performance as a result of reduced protein (RP) has been overcome in corn-based diets with essential AA and glycine (Gly) supplementation. The current study examined RP levels and Gly in wheat-based diets. An industry standard protein (SP) diet plus 3 RP diets with and without Gly supplementation, to match the SP treatment at 0.713 and 0.648% digestible Gly for the grower and finisher periods respectively, were fed to male broilers from day 10 of age. Grower CP included 22.5, 20.6, 18.3, and 17.7% (days 10-21) and finisher CP included 19.7, 17.8, 16.2, and 15.5% (days 21-35). Performance, meat yield, N efficiency, water intake, and apparent ileal digestibility of N and AA were measured. No difference in body weight gain (BWG), feed intake, or feed conversion ratio (FCR) were observed at 20% CP compared to the SP treatment. However, further reducing protein reduced BWG (P P P P P P 2 = 0.69) and finisher (R2 = 0.80) treatments. Water intake decreased (R2 = 0.83) with decreasing CP intake. Apparent ileal digestibility of AA and N were higher in RP diets (
