A total of 459  hatched Sudani ducklings (324 females + 135 male)  were taken, weighed and distributed into 9 experimental categories (36 female + 15 male) to examine the effect of metabolizable energy (ME) and crud protein (CP) levels in rearing diets on subsequently laying performance (25-41 wk of age) and hatching traits. The dietary ME levels in the starter period were 2600 (ME1), 2800 (ME2) and 3000 (ME3) kcal /kg, each contained crude protein level of 18 (CP1), 20 (CP2) and 22 (CP3) % from hatch up to 8 weeks of age , then followed by grower diets contained  2550, 2650, and 2750 kcal of ME/kg, each contained of 12, 14 and 16 % CP , respectively, from 9 up to 20 wks of age, after that one layer diet was provided to all experimental categories at 21 up to 41 wks.
Results showed that ducks body weight (BW) at 20 wks-old was (P < 0.01) elevated by rising ME in the diet through rearing phase, while higher BW was occurred by feeding medium CP level. Moreover, feed conversion ratio was (P < 0.01) improved by elevating both ME and CP level in diet from hatch up to 20 wks-old. Ducks age at 1^st  egg, 25.0% and peak of egg production was (P <  0.05) decreased as a result of feeding diet contained ME3 during rearing period, while it was decreased by feeding both CP2 and CP3 than those fed CP1in the diet. Subsequent laying measurements (egg number and mass, feed conversion) were (P < 0.01) enhanced by ME3 compared with ME2 and ME1 groups, while these improvements were occurred with CP2 only throughout the tested period (25-41 wks-old). The best values of laying parameters were occurred with ME3 and CP2 interaction. All studied hatching features were (P > 0.05) influenced by varied CP levels and the interaction between ME and CP, while different ME in diet had significant effect on fertility and embryonic mortality percentages. The results cleared that using high ME (3000 kcal/kg) with medium CP (20%) in starter diet followed by ME (2750 kcal/kg) with CP (14%) in grower diet throughout rearing phase of Sudani ducks, which should be followed by a layer diet containing 2850 Kcal, ME / kg with 17 % CP could be decreased the ducks age at sexual maturity (at first egg laid), enhanced the subsequent egg production performance and improved hatching traits.