Effects of dietary glutamine addition on growth performance, carcass characteristics and development of the gastrointestinal tract in Japanese quails

The objective of the present study was to investigate the influence of dietary glutamine (Gln) on growth performance, carcass traits and development of the gastrointestinal tract in Japanese quails. A total of 320 one day old male quails were allotted to 5 experimental equal groups in a complete randomized design, according to the added Gln content (0, 20, 30, 40 and 50 mg/kg of diet) for 42 days. Growth performance (evaluated through weight gain, feed intake and food efficiency), carcass traits (relative weights of carcasses, breast, liver and gizzard) and jejunal morphometry (measurement of villus height and width) were determined on day 21 (end of the starting period) and on day 42 (end of the growing period). Weight gains, relative carcass and breast weights were significantly increased in the Gln treated birds compared to the not supplemented controls, particularly in groups receiving 30 and/or 40 mg/kg Gln, depending on the considered period. Food efficiency was also significantly improved in parallel. In addition, the height of the jejunal villi was dramatically increased in birds supplemented with Gln compared to the controls. As a conclusion, dietary Gln supplementation has highly improved the jejunum development, leading to an increased nutrient assimilation and consequently to greater performance in Japanese quails.