Applied Research Of Chito-oligosaccharide On GIFT Tilapia, OREOCHROMIS NILOTICUS

The study was conducted to Oreochromis niloticus, two feeding trials were conducted to investigate the effect of dietary chito-oligosaccharide (COS) supplement on growth performance, non-specific immunity, gut flora, intestinal structure and hematological parameters of juvenile GIFT tilapia, The contents and results are as follows:Abstract:A 70-day feeding trial was conducted to investigate the effect of dietary chito-oligosaccharide (COS) supplement on growth performance, non-specific immun-ity and hematological parameters of juvenile GIFT tilapia, Oreochromis niloticus. COS was included at 0,1 g,3 g,5 g and 7 g/kg in trial diets, and hand-fed to satiation three times daily to triplicate groups of GIFT tilapia (30 fish/group,initial weighing approximately 3.81 g) reared in 400 L aquaria with (27±2)℃. The results were as follows:compared with the control group, weight growth rate (WGR)of fish with 5 g/kg COS diets increased significantly (P<0.05), whereas feed conversion rate (FCR) decreased significantly (P<0.05); fish fed with 3 g and 5 g/kg COS diets significantly incresead resistance with infection of Aeromonas hydrophila (P<0.01). Activity of se rum alkanline phoshpatase(AKP) significantly increased in groups feds on diets with 1 g,3 g and 5 g/kg COS (P<0.05); All groups can significantly increased activity of serum lysozyme(LSZ), superoxid dismutase (SOD), resistance with infec-tion of Aer omonas hydrophila.and decreased with TC, LDL-C by adding COS (P<0.05). Results above showed that COS could increase growth performance, nonspecific immunity and promote blood lipid metabolism. The COS supplement in diets is suggested to be 3 g/kg-5 g/kg for juvenile GIFT tilapia.Abstract:A experiment was conducted to investigate the effect of adding chito oligosaccharides (COS) in diets on growth performance, gut flora and intestinal structure of juvenile GIFT tilapia(Oreochromis niloticus). COS was added at the proportions of 0,1 g,3 g,5 g and 7 g/kg in trial diets, and hand-fed to satiation three times daily to triplicate groups of GIFT tilapia (30 fish/group, initially weighing approximately 3.81 g) reared in 400 L aquaria with the temperature of (27±2)℃. The results were as follows:compared with the control group, weight growth rate (WGR) of fish with 3 g and 5 g/kg COS diets increased significantly (P<0.05), all groups with COS saw significant increases in specific growth rate (SGR) and the digestibility of young fish to dry matter and protein (P<0.05), whereas feed conversion rate (FCR) decreased significantly (P<0.05); fish fed with 3 g and 5 g/kg COS diets showed asignificant increase in width and density of intestinal villus (P<0.05), the thickness of intestinal wall (P<0.05) of young fish was reduced by 3 g,5 g and 7 g/kg. each gradi-ent of COS could reduce the amount of colon bacillus in intestinal of young fish (P<0.05), and increase the amount of lactobacillus (P<0.05). Results above suggests that additional of COS improved the intestinal environment of young GIFT tilapia and the growth performance; and the appropriate addition amount was 0.30～0.50%.