الملخص

This experiment was conducted at the Poultry Farm of the College of Agriculture, University of Anbar , from 13/9/2025 to 25/10/2025, lasting for 42 days . The study aimed to evaluate the impact of utilizing low-protein diets supplemented with synthetic amino acids on the physiological performance of Ross 308 broiler chickens and their role in promoting environmental sustainability by reducing gas emissions. A total of 192 broiler chicks were used, randomly distributed into three dietary treatments: T1 (control) with standard protein levels (21%, 20%, and 19%) for the starter, grower, and finisher phases, respectively; while protein levels in T2 and T3 were reduced by 1% and 2% , respectively , with amino acid fortification .No statistically meaningful (P<0․05) difference was observed for the hematological parameters (Hb‚ PCV‚ RBC‚ WBC) and heterophil/lymphocyte (H/L) ratio and for blood biochemical parameters (total protein‚ albumin‚ globulin, glucose, V.LDL, LDL, HDL, Triglyc and Cholesterol)․ No negative effect was observed for renal parameters (creatinine and uric acid) and liver enzymes (aspartate aminotransferase and alanine aminotransferase (AST and ALT)․ All these suggest that metabolic and physiological homeostasis was achieved during the experimental period․ Therefore‚ a reduction of dietary crude protein without disturbing the amino acids ratio may provide an alternative way to reduce poultry production costs while also minimizing nitrogen and ammonia excretion without adversely affecting biological efficiency․