Effects Of Fish Meal Replacement By Biological Fermented Feed On Growth, Digestive And Immune Performance Of Juvenile Chinese Mitten Crab, Eriocheir Sinensis

This experiment was conducted to investigate the effect of replacement of fish meal with biological fermented feed in diets on growth, digestive and immunity performance of Chinese mitten crab. A total of 240 Chinese mitten crab with the average body weight of (5.92±0.23)g were randomly assigned to 4 groups with 3 replicates per group and 20 crab per replicate. Four isonitrogenous and isocaloric experiment diets were formulated in which biological fermented feed supplemental levels were 0,5%,10% and 15%. That was to say fish meal contained in diets at a rate of 40% was replaced by biological fermented feed at four inclusion levels of 0,12.5%,25% and 37.5%.The experiment lasted for 8 weeks. The results showed as follows:1. Weight gain rate, specific growth rate and protein efficiency ratio in the 10% biological fermented feed were significantly higher than the whole fish meal(P<0.05).And the feed conversion ratio of the 10% biological fermented feed was significantly lower than the whole fish meal(P?0.05).But the growth performance hadn't significantly increased with the increasing to 15% of the biological fermented feed in diets. Else, the different proportions of biological fermented feed in diets showed no significant difference about the feeding rate, hepatopancreas index and the survival.2. The experiment showed adding different proportions of biological fermented feed in diets was no significantly different on moisture and crude lipid content among the treatments. However, crude protein content of the 10% biological fermented feed was significantly higher than the whole fish group(P<0.05). And the ash content of the 10% biological fermented feed were significantly lower than the whole fish group(P<0.05).3. The activity of the lipase and trypsin of the hepatopancreas showed the first increasing trend,and then decreasing with the increase of biological fermented feed in inclusion levels. And the activity of the lipase of the whole fish meal was significantly lower than the other groups(P?0.05). However, the activity of the lipase had no significant difference between the three groups of 5%?10% and 15% biological fermented feed. The activity of the trypsin of the 10% and 15% biological fermented feed was significantly higher than the whole fish group(P<0.05).And the activity of the trypsin of the 10% biological fermented feed was significantly higher than the 5% and 15% biological fermented feed(P<0.05). Meanwhile, the different proportions of biological fermented feed in diets showed no significant differences on the activity of the amylase.4. The results with different proportions of biological fermented feed in diets on the the immune activity of the serum of the Chinese mitten crab showed the activity of alkaline phosphatase (AKP), acid phosphatase (ACP) and lysozyme (LSZ) of the 10% biological fermented feed were significantly higher than the whole fish meal(.P<0.05). And the activity of alkaline phosphatase (AKP) of the 5% biological fermented feed were significantly higher than the whole fish group(P<0.05). In addition, the activity of acid phosphatase (ACP) of the 15% biological fermented feed were significantly higher than the whole fish group(P?0.05).But the immune activity of the serum was no significantly improvement with the increase of biological fermented feed in inclusion levels by analyzing the immune activity in the serum.5. The activity of the T-AOC and SOD of the serum showed the increasing trend with the increase of biological fermented feed in inclusion levels. And The activity of the T-AOC of the 10% biological fermented feed and the activity of the T-AOC and SOD of the 15% biological fermented feed were significantly higher than the whole fish group(P<0.05). However, the activity of the T-AOC and SOD had no significant difference between the 10% biological fermented feed and the 15% biological fermented feed. In addition, the activity of the CAT of the 10% biological fermented feed was significantly higher than the 10% and 15% biological fermented feed(P<0.05). Compared with the whole fish group, the activity of the CAT of the 10% biological fermented feed was no significant difference. Else, the content of the MDA of the serum was increasing with the increase of biological fermented feed in inclusion levels, and the content of the MDA of the 15% biological fermented feed was significantly higher than the other groups(P<0.05).6. In hepatopancreas,with the increase of biological fermented feed in inclusion levels, the activity of the T-AOC?SOD and GSH-Px showed the first increasing trend,and then decreasing. The activity of the T-AOC?SOD and GSH-Px of the 10% biological fermented feed was significantly higher than the whole fish group(P<0.05). And the activity of the SOD of the 15% biological fermented feed was significantly higher than the group of the biological fermented feed content below 10% (P<0.05). Else, the different proportions of biological fermented feed in diets showed no significant difference on CAT and MDA. To muscle tissue, the activity of the SOD of the 10% biological fermented feed and the activity of the T-AOC and SOD of the 15% biological fermented feed were significantly higher than the whole fish group (P?0.05). However, the activity of the T-AOC and SOD had no significant difference between the 10% biological fermented feed and the 15% biological fermented feed. Meanwhile, the different proportions of biological fermented feed in diets showed no significant difference on CAT and MDA.Taken together, the biological fermented feed as the protein source can replace fish meal to feed Chinese mitten crab and the appropriate adding level is 10%.