| 360 Southern catfish juvenile(silurus meridionalis chen)were randomly divided into 24 groups,and randomly distributed to 24 cement pits(1.4×2m),21 diets were designed in this test.20 diets were fed to fish in single cement pond,while 1 diet was fed to fish in four replicate ponds to estimate inter-pond variation.The experiment lasted for 40 days.Protein,lipid and carbohydrate were varied between 33%—51%, 3%—18%,24%—33%,respectively.The aim of this study was to determine optimal macronutrient composition of formulated diets for Southern catfish(2.0±0.4g) juvenile.These results clearly showed:(1)at dietary protein 39%—48%,with corresponding to dietary lipid 6%—12%and carbohydrate 24%—30%,and with digestible energy 17.6—19.7kJ/g,Southern catfish juvenile,SGR was higher. (2)There were not affected by nutrients at different level;The lipid in muscle increased with increasing dietary lipid level and carbohydrate;At carbohydrate 33%, the carbohydrate inclusion in muscle were higher than other group(P＜0.05).(3)RBB and FWB were increased with increasing dietary lipid level,at lipid 9%—15%,the lipid in liver increased with increasing dietary lipid level;The carbohydrate content in liver were affected by dietary carbohydrate level(P＜0.05).At carbohydrate 33%,the carbohydrate inclusion in liver were higher than other group(P＜0.05);(4)GPT,TG and VLDL were not statistically difference by different lipid levels(P＞0.05).The TP of lipid15 and 18 was statistically lower than the other groups(P＜0.05),the ALB of lipid 18 statistically lower than the other groups(P＜0.05);the GLO of 15 and 18 were statisitically lower than the other groups(F＜0.05).In conclusion.The optimal dietary protein,lipid,carbohydrate,digestible energy and D/P level of Southern catfish juvenile were 39%—48%,6%—12%,26%—29%,17.6—19.7kJ/g,36.7—46.7kJ/g,respectively. |
