Effects of dietary protein levels on growth,blood biochemical parameters and body composition of Penaeus monodon

This experiment was conducted to investigate the effects of different protein contents of feed on the blood biochemical indicators and body nutritional composition of Penaeus monodon. The feed of dietary protein contents of 34%,38% and 42% were selected to feed Penaeus monodon for 54 days,and the total protein( TP),albumin( ALB),triglycerides( TG) and other biochemical indicators in blood of Penaeus monodon and the body nutritional composition were evaluated and analyzed to compare the difference of Penaeus monodon blood indicators and body nutritional composition to provide the basic data for Penaeus monodon growth and nutrition metabolism. The results showed that the specific growth rate( S GR) of Penaeus monodon demonstrated significant differences( P 0. 05) in different diet groups,SGR increased with the increase of diet protein level; the survival rate( S R) also showed significant differences( P 0. 05) in different diet groups,S R was the highest in 38% protein level group. Blood biochemical indicators of Penaeus monodon were determined by Beckman Synchron CX 5 automatic biochemical analyzer,the activity of blood glutamic- pyruvic transaminase( GPT) showed an upward trend along with the increase of diet protein levels,glutamic- oxaloacetic transaminase( GOT),and the content of total protein( TP) and albumin( ALB) were the same,and they all showed significant differences( P 0. 05) in different diet groups. Blood glucose( GLUC) levels also increased with the increase of diet protein level but the rising trend was not obvious; the level of triglyceride( TG) and the content of cholesterol( CHOL) in blood tended to be consistent in the 34% and 38% diet protein levels,and both of them increased in 42% diet protein level,while the rising trend of CHOL was more obvious. With the increase of diet protein level,the protein content of Penaeus monodon increased,meanwhile,moisture content decreased while the downward trend was not obvious( P 0. 05),and the content of ash and fat changed in a unorganized way. The above results could be used in production practice,the diary feed of more than 38% protein content level should be used in the process of aquaculture and the protein content of the feed should be increased appropriately to speed up the growth of Penaeus monodon,increase the resistance of blood on the pathogenic bacteria and virus,improve body protein deposition,in order to meet consumer demands for high protein food.