| Abstract: | The present study aims to assess the anti‐nutritional effect of pectin and to better understand rapeseed meal (RSM) as a feed ingredient for Chinese mitten crab, Eriocheir sinensis. A semipurified diet containing 280 g/kg fish meal was formulated as a control diet (DF). A second diet (DP) was supplemented with 26.7 g/kg pectin; the amount was estimated to be equal to that in the third diet (DR), which was formulated to include 400 g/kg RSM. Another diet (DRPase) was supplemented with 12 g/kg pectinase based on DR in which pectin was degraded by pectinase. The diets were randomly fed to twelve tanks of the crab for 8 weeks. Compared with the crabs fed DF, the specific growth rate, protein efficiency ratio, apparent digestibility coefficients (ADC) of dry matter and protein, activity of aspartate transaminase (AST) and trypsin (TP), and high‐density lipoprotein (HDL) in the serum decreased significantly in the crabs fed DR; the ADC of dry matter, activity of AST and serum HDL decreased significantly in the crabs fed Dp, but they were higher than in the crabs fed DR. Compared with the crabs fed DR, the ADC of dry matter, activity of AST and TP, and serum HDL increased significantly in the crabs fed DRPase. The mRNA expression activity of both Es‐pl44 and Es‐pp1 was DF < DP < DRPase < DR. These results indicate that pectin contributed to low utilization of RSM in Chinese mitten crab. |
