The Research Of Influence Of Partial Replacement Of Fish Meal By Soybean Meal In Diets For Yellow Cheek Carp(Elopichthys Bambusa)

This study was conducted to investigate the effect of partial replacement of fish meal by soybean meal on growth performance, muscle composition, plasma biochemical indices, digestive enzyme activities and gastrointestinal histology. A total of 825 yellow cheek carp with average body weight of (584.85±23.97g) were randomly distributed into 5 group with 3 replicates per group and 55 fish per replicate. Five isonitrogenous and isoenergetic diets were formulated with 0,10%,20%,30% and 40% fish meal replacement by soybean meal. The fish in the 5 group were fed the 5 experimental diets. The fish were fed twice a day (7:00 and 17:00). The mortality and amount of feed consumed of fish were recorded daily. The experiment has lasted for 8 weeks. The results suggested as follows:1) The data of evacuation of yellow cheek carp were fitted by exponential model under the condition of feeding artificial feed. The exponential function is y=105.71 e^(-0.2183x), R2=0.9609. The ILR and ISI of juvenile yellow cheek carp is similarity to adult.2) With the increasing levels of replacement of fish meal by soybean meal, there is no significant changes of mortality and condition factor (CF) of yellow cheek carp (P>0.05). The viscerosomatic index (VSI) of 10%-30% substitution group was significant lower than others (P<0.05). The weight gain rate (WGR), special growth rate (SGR) and protein efficiency ratio (PER) of fish were dropped and the feed conversion ratio(FC) was raised (P<0.05) when fish were fed the diet which more than 20% fish meal were replaced by soybean meal.3) No significant differences of muscle composition were observed in each treatment group (.P>0.05), However, the muscle lipid content of yellow cheek carp has showed upward trend after downward.4) With the level of replacement raise, the superoxide dismutase (SOD) activity gradually increased, the lysozyme (LYZ), Triglyceride (TG) and Glucose (Glu) has showed downward trend after upward, however, the total cholesterol (TC) has the opposite trend. The extremum was observed on 20% substitution group. There are no significant differences in the proportion of the replacement of 10%-30% (P>0.05).5) The digestive enzyme activities of yellow cheek carp were significantly influenced by replacement of fish meal by soybean meal (P<0.05). With the proportion of replacement rising, the digestive enzyme activities of liver and intestinal has showed upward trend after downward. The most optional replacement ratio is 20%.6) The lipase activities of yellow cheek carp was high, and the protease activities was much higher than amylase. It indicated that the yellow cheek carp is the carnivorous or partial carnivorous animal.7) The liver was not affect by the inclusion of dietary soybean meal. The varying degree of injury was observed in the high fish meal and low fish meal group, and there was no affect in other groups.In summary, it was necessary to replace fish meal by soybean meal, and the highest replacement proportion was 30%, and The most optional replacement proportion is 20%.