Study On The Requirements Of The Dietary Protein And Lipid In Two Sizes Of Pacific White Shrimp

Growth performance, feed utilization, body composition, hemolymph biochemical and immune index were evaluated to determine the requirements of the dietary protein and lipid in two different sizes of Litopenaeus vannamei (initial weight0.5g and7.9g, respectively), the brief summarys are as follows:1. Six diets contenting crude protein (dry matter%)29.31,33.19,37.11,41.45,45.58and49.03were confected useing fish meal, gelatin, casein and wheat gluten as the main protein source. An8-week feeding trial was conducted to determine dietary protein requirment of white shrimp with initial body weight0.52g useing these diets. The results showed that dietary protein level had significant effect on weight gain, specific growth rate, protein efficiency, feed conversion ratio and condition factor (p<0.05), but had no significant effect on survival and hepatopancreas index of white shrimp(p>0.05). Significant differences were found in body composition (p<0.05) of white shrimp except moisture and whole body protein (p>0.05). The total cholesterol, triglyceride, SOD, PO and ALT in hemolymph were significantly affected (p<0.05) by dietary protein level, while there were no significant difference in total protein and AST (p>0.05). A regression equation for the specific growth rate showed that the optimum dietary protein requirement was determined to be38.6%. for Pacific white shrimp in size of0.5g.2. A6-week feeding trial was conducted to determine dietary protein requirment of Pacific white shrimp with initial body weight7.93g useing same diets as experiment one. The results showed that dietary protein level had significant effect on weight gain, specific growth rate, protein efficiency and feed conversion ratio (p<0.05), but had no significant effect on survival, hepatopancreas index and condition factor of white shrimp (p>0.05). Significant differences were found in body composition (p<0.05) of white shrimp except lipid, ash and whole body moisture (p>0.05). The AKP, SOD, PO and AST in hemolymph were significantly affected (p<0.05) by dietary protein level, however there was no significant difference in ALT (p>0.05). A regression equation for the specific growth rate showed that the optimum dietary protein requirement was determined to be36.8%for Pacific white shrimp in size of7.9g.3. Six diets contenting crude lipid (dry matter)4%,6%,8%,10%,12%and14%were confected useing fish meal, wheat gluten, gelatin and casein as the main protein source. An8-week feeding trial was conducted to determine dietary lipid requirment of white shrimp with initial body weight0.58g useing these diets. The results showed that dietary lipid level had significant effect on weight gain, specific growth rate, protein efficiency, feed conversion ratio, condition factor and hepatopancreas (p<0.05), but had no significant effect on survival index of white shrimp (p>0.05). There were no significant differences in protein, lipid, ash and moisture in whole body and trail muscle (p>0.05) but the trail muscle ash (p<0.05). The total cholesterol, total protein, SOD, PO, AST and ALT in hemolymph were significantly affected (p<0.05) by dietary lipid level, however there was no significant difference in triglyceride (p>0.05). Therefore,6%dietary lipid level may be optimum for Pacific white shrimp in size of0.5g.4. An6-week feeding trial was conducted to determine dietary lipid requirment of white shrimp with initial body weight7.93g useing same diets as experiment three. The results showed that diet lipid level had significant effect on weight gain, specific growth rate, protein efficiency and feed conversion ratio (p<0.05), but had no significant effect on survival, hepatopancreas index and condition factor of white shrimp (p>0.05). There were no significant differences in protein, lipid, ash and moisture in whole body and trail muscle (p>0.05) except the trail lipid and whole body moisture (p<0.05). The AKP, SOD, PO, AST and ALT in hemolymph were significantly affected (p<0.05) by diet lipid level. Therefore,6%dietary lipid level may be optimum for white shrimp in size of8g to20g.