Effect of in ovo Feeding of Graded Levels of L-glutamine on Blood Biochemistry, Colour and Texture of Selected Muscles, Carcass Quality Traits of Coloured Chicken during Heat Stress

Glutamine (Gln) has gained attention as a promising feed additive due to its ability to promote the growth of intestinal villi. Glutamine, a non-essential amino acid is found predominantly in the blood and intracellular space, serves as a vital energy source for rapidly dividing cells, particularly enterocytes. Early in ovo supplementation with glutamine (Gln) has been found to promote the development and maturation of the intestinal epithelium and skeletal muscle, offering both immediate and long-term benefits after hatching. The present study was designed to study the effect of in ovo feeding of graded levels of L-Gln supplementation on blood biochemistry, colour and texture of selected muscles and carcass quality traits of coloured chicken. Four hundred and eighty six fertile eggs of coloured chicken (Chabro) were set for incubation. On 18th day of incubation, fertile eggs were divided into five treatment groups – un-injected control (T1), injected with distilled water (Sham Control) (T2), injected with 0.5 ml of 0.5% L-glutamine (Gln) (T3), injected with 0.5 ml of 1% Gln (T4) and injected with 0.5 ml of 2% Gln (T5). After hatching, three hundred sixteen day-old straight-run colored chicks were further sub-divided into three replicates with fifteen birds in each replicate. Birds were reared for 8 weeks and kept on a Basal or Control diet (BIS, 2007; broiler starter diet, 22% CP and 3100 ME till 4 weeks and thereafter broiler finisher diet, 20% CP and 3200 ME till 8 weeks of age). Average temperature, RH and THI during the experiment was 34.340C, 64.14% and 86.76 respectively. After 4 weeks of age, serum AST was significantly lower (P