Effects of glucocorticoid-induced stress on absorption of glycylsarcosine in jejunum of broilers

Abstract

This study was conducted to investigate the effects of stress on the absorption of glycylsarcosine in the jejunum of broilers, as well as the underlying mechanisms. A glucocorticoid analogue, dexamethasone (DEX), was chosen to simulate the effects of endogenous glucocorticoids. Two hundred 21-day-old male Arbor Acre broilers were randomly allotted to 4 groups with 5 replicates in each group and 10 birds per replicate by a completely randomized assignment involving a single factorial arrangement of injection dose DEX. The broilers were injected with 1-mL DEX (0.1-, 0.5-, and 2.5-mg/kg BW) or saline subcutaneously in the abdomen 1×/d for 7 d. The broilers were weighed, killed, and sampled at 28 days old. The results showed that DEX dose-dependently reduced growth and endogenous corticosterone content in the plasma of the broilers (P < 0.05). DEX decreased absorption of glycylsarcosine by jejunum brush border membrane vesicles and gut sacs (P < 0.05). DEX treatment increased the crypt depth of the jejunum, decreased the villus height, absorption area, and ratio of villus height to crypt depth (P<0.05). Effect of dexamethasone on villus width was not obvious (P > 0.05). It was concluded that DEX reduced the absorption of glycylsarcosine in the jejunum of broilers.