Effect Of Dietary Cottonseed Meal Level On Growth, Some Physiological And Biochemical Indices Related In Juvenile Chinese Mitten-handed Crab, Eriocheir Sinensis

In this paper, cottonseed meal(CSM) was systematically evaluated based on its content of nutrient,anti-nutritional factor (gossypol) and its effects on growth, body composition, digestive enzyme activity, micro structure and ultrastructure of gut and hepatopancreas as a protein source for juvenile Chinese mtten-handed crab(Eriocheir sinensis). The results were followed.1. Effect of dietary CSM level on growth,physiology and chemistry in juvenile Chinese mitten-handed crab, Eriocheir sinensis1.1 Effect of dietary CSM level on growth performance,body composition of E. sinensisThe effect of CSM as a partial or total replacement of other plant protein source meal (FM) was studied in E. sinensis. Three experiment diets containing a gradient of CSM were fed to duplicate group of crab over 70 days. Crabs fed diets of total fishmeal(FM) served as control and containing 20% (CSM200),40%(CSM400), and 66 (CSM660) of CSM.After fed diets with different proportions of CSM, SGR of E. sinensis significantly decreased with the increasing of CSM in the diet (P<0.05). SR, SGR and PER of the control were significantly higher than treatment groups (P<0.05). As the concentration of CSM increased in the diet, There was not a tendency of decreasing of SR with the incorporation of CSM levels increasing in the treatment diets. FCR of the control were significantly Lower than treatment groups (P<0.05),along with the increasing content of CSM in the diets, there was an decreasing FCR,but no significant difference was observed between treatment groups (P>0.05). The results of body composition of E.sinensis showed that with increasing concentration of CSM in the diets, there was an decreasing protein content, significant differences were observed between the control and group CSM660 (P<0.05). Ash content of the control were significantly lower than treatment groups (P<0.05).1.2 Effect of dietary CSM level on the digestive enzyme activity of gut and hepatopancreas of E. sinensisThe result showed that trypsin activity in gut of the control E. sinensis were significantly higher than treatment group CSM660 (P<0.05), no significant difference was observed in the control, group CSM200 and CSM400(P>0.05), and significant difference was observed between CSM660 and other groups(p<0.05). The trypsin activity in hepatopancreas of the control E. sinensis were significantly higher than treatment groups(P<0.05), no significant difference was observed between group CSM200 and CSM4oo(P>0.05), and significant difference was observed in other groups(P<0.05). And pepsin activity in gut and hepatopancreas of the control E. sinensis were higher than treatment groups (P<0.05),but no significant differences were observed in all groups(P>0.05).1.3Apparent digestibility of diets with different CSM concentration for E. sinensisAfter fed diets with different proportions of CSM, the apparent digestibility of dry matter of the control were significantly higher than treatment groups(P0.05),but no significant differences were observed between group CSM400 and CSM660 (P>0.05). There was a tendency of decreasing of apparent digestibility of protein with the incorporation of CSM proportions increasing in the treatment diets, significant differences were observed in all groups(P0.05).1.4 Effect of dietary CSM level on the microstructure and ultrastructure of gut and hepatopancreas of E. sinensisAfter 70 days feeding with diet containing 474mg.kg-1 gossypol acetate, the ultrastructure of hepatopancreas showed that cell organells of hepatopancreas were damged by dietary gossypol acetate, which included mitochondria cristaes partly disintegrated and then fully disintegrated; lysosomes increased;Swoollen endoplasmic reticulum and mostly were smooth endoplasmic reticulum; intimate membrane became disorganized; nuclear membrane invaginated and nuclear matter extravasated.The ultrastructure of gut showed that shrunken fold increased in the intestinal mucosa and sparse microvilli.The microstructure of hepatopancreas of E. sinensis showed disorganizated some cells disorganizated and the pieces of cells appeared in lumen,the number of vacuoles increased and their volumes augmented.2. Effects of gossypol acetate on growth, physiology and chemistry in E. sinensis2.1 Effects of gossypol acetate on growth performance,body composition of E. sinensisIn order to investigate the anti-nutritional function of different levels dietary gossypol, four experimental diets which included control,144 mg.kg-1 gossypol,288 mg.kg-1 gossypol, 474 mg.kg-1 gossypol were formulated(named diet FGo, FG144, FG288, FG474 respectively) and fed to E. sinensis for 10 weeks.After fed diets with different proportions of gossypol acetate,survival rate(SR) of E. sinensis decreased with the increasing of gossypol acetate in the diet, and significant difference was observed between the control (FGo),group FG288 and FG474 (P<0.05). Specific growth rate(SGR) and protein efficiency ratio(PER) of the control were significantly higher than treatment groups (P<0.05). As the concentration of gossypol acetate increased in the diet, PER and SGR descended. Feed conversion ratio(FCR) of the control were significantly Lower than treatment groups (P<0.05). with increasing content of gossypol acetate in the diets, there was an decreasing FCR. The results of body composition of E.sinensis showed that with increasing concentration of gossypol acetate in the diets, there was an decreasing moisture,protein and lipid content, no significant differences were observed in the treatment groups(P>0.05). Ash content of the control were significantly lower than treatment groups (P<0.05), and significant difference was observed between treatment groups (p<0.05).2.2 Effects of gossypol acetate on the digestive enzyme activity of gut and hepatopancreas of E. sinensisThe result showed that trypsin and pepsin activity in hepatopancreas of the control E. sinensis were significantly higher than treatment group FG474 (P<0.05). There was a tendency of decreasing of trypsin and pepsin activities with the incorporation of gossypol acetate levels increasing in the diets, no significant differences were observed in the treatment groups(P>0.05).And trypsin and pepsin activity in gut of the control E. sinensis were higher than treatment groups (P<0.05),but no significant differences were observed in all groups(P>0.05).2.3Apparent digestibility of diets with different gossypol acetate concentration for E. sinensisAfter fed diets with different proportions of gossypol acetate, the apparent digestibility of dry matter of group FG474 were significantly lower than group FG144 (P<0.05),but no significant differences were observed in the control, group FG144 and FG288(P>0.05),and also in the control, group FG474 and FG288-There was a tendency of decreasing of apparent digestibility of protein with the incorporation of gossypol acetate levels increasing in the treatment diets, significant differences were observed in the treatment groups(P<0.05).2.4 Effects of gossypol acetate on the microstructure and ultrastructure of gut and hepatopancreas of E. sinensisAfter 70 days feeding with diet containing 66% CSM, the ultrastructure of hepatopancreas showed that cell organells of hepatopancreas were damged by dietary gossypol acetate, which included mitochondria cristaes partly disintegrated and then fully disintegrated; lysosomes increased; Swollen endoplasmic reticulum and mostly were smooth endoplasmic reticulum; intimate membrane became disorganized; nuclear membrane invaginated and nuclear matter extravasated. The ultrastructure of gut showed that shrunken fold increased in the intestinal mucosa and sparse microvilli. The microstructure of hepatopancreas of E. sinensis showed disorganizated some cells disorganizated and the pieces of cells appeared in lumen,the number of vacuoles increased and their volumes augmented.