Dietary Myo-inositol, Folic Acid And Thiamine Requirement For Grass Carp (Ctenopharyngodon Idellus) Fingerling

The main research in this paper were done to investigate dietary myo-inositol (MI), folic acid and thiamine requirement for grass carp (Ctenopharyngodon ideUus) fingerling. The content as follow:1. An 9-week growth experiment was conducted to estimate the requirement of myo-inositol for grass carp fingerling. Half-purified basal diets were formulated using the fish meal, glutin and casein as the protein source. MI was supplemented at 0, 50, 100, 200, 400, 800, and 1600 mg/kg diet in the basal diet. Each diet was fed to triplicate groups of grass carp with initial average weight (4.78±0.18)g. Grass carp fingerling fed diets supplemented with =200 mg MI/kg had significantly higher (P＜0.05) weight gain rate, specific growth rate, total cholesterol and low density lipoprotein cholesterol concentration in serum than the control group fed diet supplemented without MI. In contrast, the test groups had significantly lower (P＜0.05) triglycerides concentration in serum than the control group. Also grass carp fingerling fed diets with 200 mg MI/kg and 400 mg Ml/kg had significantly lower (P＜0.05) feed conversion rate and protein efficiency ratio than the control group. Supplementation of dietary MI had no effect on survival rate, high density lipoprotein cholesterol concentration in serum and the whole fish biochemical composition of grass carp fingerling (P＞0.05). Weight gain rate, total cholesterol concentration, triglycerides concentration and low density lipoprotein cholesterol concentration of grass carp analyzed by broken-line regression indicated that the dietary MI requirement for growing grass carp was approximately 166～214 mg/kg diet.2. A feeding trial was conducted to determine the folic acid requirement of grass carp fingerling. Purified basal diets were formulated using vitamin-free casein and glutin as the protein source. Different levels of folic acid (0, 0.5, 1.0, 2.0, 5.0, 10 and 20 mg folic acid/kg diet) were graded in the basal diet, resulting in seven dietary treatments in the experiment. Each diet was fed to triplicate groups of grass carp with initial average weight (5.78±0.17)g for 8 weeks. Grass carp fingerling fed diets supplemented with=5mg folic acid/kg diet had significantly higher (P＜0.05) weight gain rate, feed efficiency, hemoglobinassay concentration and platelet counting in blood than the control group fed diet supplemented without folic acid. In contrast, the test groups had significantly lower (P＜0.05) triglycerides, total cholesterol and low density lipoprotein cholesterol concentration in serum than the control group. Supplementation of dietary folic acid had no effect on survival rate, total protein and high density lipoprotein cholesterol concentration in serum and red blood cell counting in blood (P＞0.05). Weight gain rate, triglycerides concentration, total cholesterol concentration, hemoglobinassay concentration and platelet counting analyzed by broken-line regression indicated that the requirement for dietary folic acid in rearing grass carp was approximately 3.63～4.29 mg/kg diet.3. A feeding trial was conducted to determine the thiamine requirement of grass carp fingerling. Purified basal diets were formulated using vitamin-free casein and glutin as the protein source. Different levels of thiamine (0, 0.5, 1.0, 2.0, 5.0, 10.0, 20.0 and 40.0 mg thiamine/kg diet) were graded in the basal diet, resulting in eight dietary treatments in the experiment. Each diet was fed to triplicate groups of grass carp with initial average weight (10.66+₀.21)g for 12 weeks. Grass carp fingerling fed diets supplemented with=1.0mg thiamine/kg diet had significantly higher weight gain rate, specific growth rate, feed efficiency, protein efficiency ratio, triglycerides and total cholesterol concentration in serum than the control group fed without thiamine supplement (P＜0.05). In contrast, the test groups had significantly lower glucose concentration in serum than the control group (P＜0.05). Grass carp fingerling fed diets supplemented with =0.5mg thiamine/kg diet had significantly lower pyruvic acid concentration than the control group (P＜0.05). Contrarily, the test groups had significantly higher lactate dehydrogenase than the control group (P＜0.05). Grass carp fingerling fed diets supplemented with =5.0mg thiamine/kg diet had higher hepatic thiamine concentration than the other groups. Supplementation of dietary thiamine had no effect on survival rate and the whole fish biochemical composition of grass carp fingerling (P＞0.05). Weight gain rate, feed efficiency and hepatic thiamine concentration analyzed by broken-line regression indicated that the requirement for dietary thiamine in rearing grass carp were respectively 1.19 mg/kg, 1.16mg/kg and 4.49mg/kg diet.