Nonruminant Nutrition: Amino Acids 1

This study was conducted to evaluate effects of supplemental L-glutamine (Gln) and L-glutamate (Glu) on growth and physiological responses in broiler chickens. Within 8 h after hatching (36.1 ± 1.1 g BW), 480 broiler chickens were allotted randomly to 6 dietary treatments: NC (without Gln or Glu), GN5 (with 0.5% Gln), GN10 (with 1.0% Gln), GU5 (with 0.5% Glu), GU10 (with 1.0% Glu), and AG10 (with 1.0% AminoGut, consisting of L-Gln >10% & L-Glu >10%, Ajinomoto). Each treatment had 8 replicates with 10 birds per cage. Diets were fed ad libitum for 6 wk. Body weight and feed intake were measured weekly. At the end of wk 1 and 6, one bird per cage was selected randomly to measure the weights of gut, breast muscle, thigh muscle, liver, and abdominal fat pad, and to obtain blood samples. Jejunum samples from wk 1 were used to measure villus height and crypt depth. Blood samples from wk 1 and 6 were used to measure plasma IgG and IgA concentration. Initial BW did not differ among treatment groups. During the entire period, weight gain of GN10 was greater (P < 0.05) than those of GN5, GU5, and NC. The weight gain of AG10 was greater (P < 0.05) than that of NC. Feed intake of birds did not differ among treatment groups during starter, grower, and finisher phases. There was no difference in feed:gain among treatment groups during the entire period. At the end of wk1, villus height or crypt depth of birds did not differ among treatment groups. There were no difference in the % weight of each tissue among treatment groups when measured at the end of wk 1 and wk 6. Plasma IgA concentration of AG10, GN5, and GU5 were greater (P < 0.05) than that of NC at wk 6. Plasma IgG concentration of AG10 was greater (P < 0.05) than that of other treatment groups at wk 6. This study shows potential benefits of supplemental glutamine or AG to broiler chickens.