Abstract:【Objective】To investigate the effects of dietary protein and energy levels on digestive enzyme activities in the jejunal fluid of Muscovy duck.【Method】A 3×3 factorial and completely randomized design was conducted. Totally 27 male Muscovy ducks were randomly divided into 9 groups with 3 ducks per group, and fed diets with 9 different compositions of energy and protein. Jejunal digesta was collected by fistula surgery and the activities of amylase, trypsin, chymotrypsin and lipase in jejunal fluid were determined.【Result】With the increase of energy level, trypsin activities in high and medium energy groups were significantly higher compared with low energy group(P<0.05), while chymotrypsin, amylase and lipase activities did not differ significantly. With the increase of crude protein level, trypsin activities in high and medium protein groups were significantly higher compared with low protein group(P<0.05), chymotrypsin activity in high protein group was significantly higher compared with low protein group(P<0.05), while amylase and lipase activities did not differ significantly. Protein and energy levels had no obvious interaction effect on digestive enzyme activities in the jejunal fluid of Muscovy duck.【Conclusion】Under this experimental condition, energy level has a significant effect on trypsin activity, and protein level has a significant effect on trypsin and chymotrypsin activities. Neither energy nor protein level has significant effect on amylase and lipase activities.