Glutamine-supplement Diet Maintains Growth Performance and Reduces Blood Corticosterone Level in Cage-reared Growing Chicks

Abstract

Supplementation with glutamine(Gln) has beneficial effects on intestinal and immune functions. Cage-reared chicks suffer from various stressors during early growth, but the effect of Glnsupplementation on growth performance and stress hormones is uncertain. We investigated theeffect of Gln on growth performance and blood corticosterone levels in Hyline chicks. Groupsof 3-day-old chicks were fed one of three diets: normal feed(CTL group), normal feedsupplemented with a low level of Gln, or normal feed supplemented with a high level of Gln. Growth and various physiological and biochemical parameters related to stress were assessed. Onday 30, after a 24-h fast, blood was analyzed for corticosterone and other parameters, includingglutamic oxaloacetic transaminase, gamma-glutamyl transpeptidase, total bilirubin, lactatedehydrogenase, total cholesterol, high-density lipoprotein cholesterol, blood urea nitrogen, bloodtotal protein, and inorganic phosphate. Growth performance was maintained in Gln supplementedgroups. The corticosterone level was decreased in the two groups receiving Gln supplementationcompared to the CTL, and all other humoral factors did not differ between the groups. Wesuggest that Gln supplementation is a safe and useful strategy for reducing the effects of stressin cage-reared chicks.