THE EFFECTS OF GLUTAMINE AND GLUTAMIC ACID VS MICROORGANISM PRODUCING GLUTAMIC ACID SUPPLEMENTATION ON PERFORMANCE AND INTESTINAL MORPHOLOGY OF BROILER CHICKENS

This study evaluated the effects of dietary supplementation with glutamine (Gln), glutamic acid (Glu), and glutamic acid-producing bacteria on broiler chickens, focusing on growth performance, intestinal morphology, carcass characteristics, some blood measurements and economic efficiency. A total of 324 unsexed Ross 308 broiler chicks (average initial weight: 41.11 g) were assigned on day 5 to 42 floor pens (12 birds per pen), with three replicate pens per treatment. Birds were managed under a three-phase feeding program: starter (days 5–10), grower (days 11–24), and finisher (days 25–42), with diets formulated to meet broiler nutritional requirements. The treatments were as follows G1 (Control): Chicks were fed the basal diet, G2 : G1 plus 0.05% Glu, G3 : G1 plus 0.1% Glu, G4 : G1 plus 0.05% Gln, G5 : G1 plus Gln 0.1%, G6 : G1 plus 1cm3\ Kg diet biological sources (2-Bacillus subtilis), G7 : G1 plus 1cm3\ Kg diet biological sources (2-Bacillus zero), G8 : G1 plus 1cm3\ Kg diet biological sources (Enterococcus faecium) and G9 : G1 plus 1cm3\ Kg diet biological sources (Enterococcus zero). Results indicated that 0.05% Gln (G4) supplementation numerically enhanced body weight gain (BWG) and feed conversion ratio (FCR), while also improving intestinal health, as evidenced by increased villus height (VH) and a higher VH-to-crypt depth (VH/CD) ratio. Carcass characteristics were not significantly affected in all groups. Also, results indicated that the liver functions (ALT, AST), serum antioxidant (SOD, GPX) and the European production efficiency factors (EPEF) improved by 0.05% Gln supplementation