Effect Of Four Plant Protein Source On The Growth Performances, Amino Acid Retention And Non-specific Immunity Of Shrimp Litopenaeus Vannamei

Four plant protein source such as soybean meal, peanut meal, cottonseed meal and rapeseed meal were measured on Litopenaeus vannamei. In the research, two experimental diets were designed. In the first diet, 27% soybean meal, 24% peanut meal, 24% cottonseed meal and 31% rapeseed meal were used respectively on an iso-nitrogenous basis in the SBM, PM, CSM and RSM group, which contained 30% fish meal. A fish meal based diet (FM) contained 46% fish meal. Commercial feed was used as control. In the second diet, cottonseed meal and rapeseed meal were mixed as the proportion of 1:1, the soybean meal and peanut meal were mixed 2:1. The mixture of soybean meal and peanut meal (S) was replaced by the mixture of cottonseed meal and rapeseed meal (C), which was increased from 5% to 22%. Six experimental groups were designed, which contained 25% and 20% fish meal respectively. Litopenaeus vannamei mean (initial weight 0.6g) were fed with two experimental diets for a 8-week period in the indoor culture system, and the growth performances, amino acid retention efficiency and some non-specific immune indices were measured.Results showed that Litopenaeus vannamei fed the diets containing 27% soybean meal and 24% peanut meal had the similar growth performance as these fed a fish meal based diet and commercial feed (P>0.05). The growth performance of the shrimp fed the diet containing 24% cottonseed meal decreased significantly compared with FM based diet (P<0.05), not significantly with the commercial feed (P>0.05). There was significant decrease of the growth performance of shrimp fed with RSM compared with FM as well as commercial feed (P<0.05). When the mixture of cottonseed meal and rapeseed meal increased from 5% to 22%, it showed no significant difference of the growth performance of shrimp fed with all the experimental diets (P>0.05), but poorer than the commercial feed (P>0.05).The content of essential amino acid (TEAA) in the muscle of shrimp fed with the SBM and PM was no significant difference with the FM (P>0.05), but the use of the CSM and RSM resulted the significant decrease of TEAA in the muscle (P<0.05). Among six groups of the second experimental diet, the TEAA of the shrimp fed with the diet containing 25% fish meal, 20% mixture of soybean meal and peanut meal (S), and 15% mixture of cottonseed meal and rapeseed (C) was maximum, there were no significant difference in the other groups (P>0.05).The shrimp fed with PM had much higher essential amino acid retention efficiency (ERE) in the muscle than the FM as well as commercial feed (P>0.05), which fed with SM was lower than the FM, higher than the commercial feed, but there were no significant differences (P>0.05). The ERE in the muscle increased by the increase of the mixture of cottonseed meal and rapeseed, which fed with the diet containing 25% fish meal, 20% mixture of soybean meal and peanut meal (S), and 15% mixture of cottonseed meal and rapeseed was maximum, then the ERE decreased.There were different effects on non-specific immunity because of incorporation of different plant protein soures. There were no significant differences of protein concentration in the serum in the SM, PM, CSM, RSM. But the increase of the mixture of cottonseed meal and rapeseed resulted in the decrease of the protein concentration. The use of the rapeseed meal resulted in the significant decrease of the phenoloxidase (PO) activities in the serum (P<0.05), which of the other groups had no significant difference The superoxide dismutas (SOD) activities in the two experimental diets were not significant difference respectively (P>0.05). The activities of catalase (CAT) of the CSM group were significantly lower than the commercial feed and RSM. In the six groups of the second experimental diet, the CAT activities were no significant differences along with the increase of the mixture of cottonseed and rapeseed meal.The glutamic oxaloacetate transaminase (GOT) and glutamic pyruvate transaminase (GPT) activities in the hepatopancreas in the FM, SBM, PM, CSM and RSM were not significantly different (P>0.05), but significantly higher than commercial feed (P<0.05). The GPT activity in serum in the RSM group was higher than the other groups. The GOT and GPT activities in the serum and hepatopancreas in the second experimential diets were not significantly different (P>0.05).