The Effects Of Soybean Protein Source On Growth Performance And Intestinal Immune Of Juvenile Jian Carp(Cyprinus Carpio Var.Jian)

Two trials were conducted to study the the effects of soybean protein isolate(SPI) and dehulled soyabean meal(DSBM) on growth performance and intestinal immune of juvenile Jian c&rv(cyprinuscarpio VemJiari). In trial 1, 720 juvenile Jian carps with initial weight 11.34?.16g were averagely allocated to 5 treatments with 3 replications , feeding diets with fish meal protein substituted by 0,40,60, 80 and 100% SPI protein respectively. In trial 2, 720 juvenile Jian carps with initial weight 10. 29±0. 10g were averagely allocated to 5 groups with 3 replications, feeding diets with fish meal protein respectively replaced by 0, 25, 50, 75 and 100% DSBM protein.In trial 1, weight gain, SGR, feed intake, feed intake / weight gain, hepatopancreas weight, intestine weight, intestine length, height of proximal and distal intestinal folds were significantly affected by the dietary SPI level (P<0.05). Weight gain, SGR, feed intake, hepatopancreas weight, intestine weight, intestine length, height of proximal and distal intestinal folds significantly decreased with the.dietary SPI levels increasing(P<0.05), while feed intake / weight gain increased (P<0.05). There was a significant correlation between SGR and feed intake or feed intake / weight gain (rl =+0.9750, P<0.01; r2=-0.9480, P<0.01). The significant correlation also existed between feed intake / weight gain and intestine weight or intestine length or height of proximal and distal intestinal folds (rl=-0.9480?P < 0.05; r2=-0.9000, P<0.05; r3=-0.9650, P<0.01; r4=-0.8820, P<0.05) . Pathological disruption of the proximal and distal intestine was regressively observed in fish given diets with fish meal protein substituted by SPI protein over 60%, which was characterized by sloughing of epithelium, widening of centra stroma and increasing amounts of leukocytes in the lamina propria, et al. Weight of head kidney, post kidney and spleen increased significantly while dietary SPI protein increasing. Survival rate, lysozyme activity as well as antibody levelof mid and distal intestine were affected significantly (P<0. 05) , too.In trial 2, weight gain, SGR, feed intake and feed intake / weight gain were significantly affected by and linely correlated with the dietary DSBM protein level (rl=-0, 9400, P<0.01 ;r2=-0.8980,P < 0.05;r3=+0.9170, P<0.05). There was a significant correlation between SGR and feed intake or feed intake / weight gain (rl= + 0.9720, P < 0.01; r2=-0.9910, P < 0.01). Hepatopancreas weight, intestine weight, intestine length, height of proximal and distal intestinal folds significantly decreased with the dietary DSBM level increasing(P<0.01).The significant correlation also existed between feed intake / weight gain and intestine weight or intestine length (rl=-0.9420, P<0.05; r2=-0.9610, P<0.01) . Similar pathological disruption of the proximal and distal intestine was observed in fish given diets with fish meal protein substituted by DSBM protein over 50%. Weight of head kidney, post kidney and spleen increased significantly while dietary DSBM protein increasing (P<0.01). Survival rate, lysozyme activity as well as antibody content of mid-intestine and distal intestine were affected significantly (P<0.05) .too.In summary, dietary SPI protein or DSBM protein resulted in growth impairment of juvenile Jian carps through decreasing feed intake and utilization. The decreasing of digestible ability was due to intestinal growth suppression, pathological disruption of the intestinal tract and intestinal folds shortening accompanied by increasing dietary SPI or DSBM level. The pathological disruption of the intestinal mucosal involved immunological mechanisms, which lead to deceased survival rate in consequence at high SPI and DSBM protein level. In a diet for 10-35g juvenile Jian carps with a total protein level of 33%, SPI and DSBM can be respectively used to replace 40% and 25% of fish meal protein without negative effects on feed utilization.