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This study was conducted to test the effects of supplemental L-Met (CJ Corp, Seoul, Korea) on redox status, gut development, and growth performance of turkey poults compared with supplemental DL-Met. Three hundred eighty five newly hatched turkey poults were weighed and randomly allotted to 5 treatments in a completely randomized design for 28 d, including a basal diet (BD), the BD +0.145% DL-Met or L-Met, the BD + 0.285% DL-Met or L-Met (representing 60, 75, and 90% of NRC digestible Met + Cys requirement). Feed disappearance and BW were measured weekly. Liver, duodenum, and jejunum samples were collected from 2 random selected birds in each cage on d 7 and 28. Hepatic tissue and duodenal mucosa were used to measure glutathione (GSH), total antioxidant capacity (TAC), protein carbonyl (PC), and malondialde-hyde (MDA) as indicators of the redox status. Duodenal and jejunal tissues were used to evaluate morphology. Data were analyzed using the Mixed procedure in SAS. A multilinear regression analysis was used to evaluate the relative bioavailability (RBA) of L-Met to DL-Met. Overall, weight gain (690 to 746 g) and feed intake (1123 to 1248 g) were increased (P < 0.05) as increasing digestible Met + Cys levels from 60 to 90% of the NRC requirement. Birds with L-Met tended (P = 0.053) to have decreased F:G (1.70 to 1.63) compared with birds with DL-Met. Rates of decrease in F:G were different (P < 0.05) between birds with DL-Met and L-Met. Supplementing Met regardless of sources decreased (P < 0.05) MDA (3.29 to 2.47 μmol/g protein) in duodenal mucosa compared with birds in the BD. Supplementing L-Met tended (P < 0.094) to decrease MDA (1.27 to 1.16 Limol/g protein) in hepatic tissues compared with the supplementation of DL-Met. Other oxidative status markers including GSH, TAC, and PC were not affected by Met sources. Supplementation of Met either from DL or L forms did not affect morphology of duodenum and jejunum on d 7 and 28. In conclusion, supplementation of Met enhanced the growth performance and reduced oxidative stress in the gut of turkey poults during the first 28 d of age. Use of L-Met can potentially enhance feed efficiency and reduce systemic oxidative stress compared with the use of DL-Met in turkeys. [ABSTRACT FROM AUTHOR]