| Ninety-six crossbred ducks fed with shrimp by-products (SBP) were used in this experiment, in which four experimental diets were fed following a factorial design, with 3 replicates of 4 ducks (1:1 sex ratio) in one experimental unit. The first factor was the digestion technique (ileal and total tract digestibility) and the second factor was the diets. Four diets included a basal diet (SBP0), which consisted of fish meal 20% (FM), broken rice 80% (BR) and the other three diets, in which the content of FM was 25.0, 50.0 and 100% of the FM level in the basal diet and was replaced by ensiled shrimp by-products corresponding the SBP1, SBP2 and SBP3 diet, respectively. Daily intakes of ether extract (EE) and fiber fractions increased with increasing levels of SBP. The apparent total tract digestibility of dry matter (DM), organic matter (OM), ether extract (EE), and nitrogen-free extract (NFE), as well as nitrogen retention, decreased linearly with increasing SBP (P <0.05). The apparent total tract digestibility of the majority of individual amino acids was greater than their apparent ileal digestibility (P <0.05). Individual amino acid digestibility decreased linearly (P<0.05) as the dietary level of SBP increased