Study On Application And Mechanism Of NSP-Enzyme Supplemented In Diets Of Tilapia

All trials were conducted to investigate the effects and mechanism of Non-starch polysacchrides enzyme supplemented in diet of hybrid tilapia .Exp.1 was conducted to study the effect of feeding water on the water stability of NSP-enzyme sprayed.The results showed that the NSP-enzyme activity in 1 hour was still high ,and this is very important qualification for other deep study.Exp.2 was conducted to study the effect of NSP-enzyme on Growth Performance,Nutrients Digestibility, blood biochemical and immunity index of Hybrid Tilapia Oreochromis niloticus ×O. aureus. All of 560 fish were randomLy allotted to four groups containing 7 replicates and fed rations with NSP-enzyme of grade levels (0, 0.01%, 0.02% and 0.04%).The results showed that:(1)Supplement of NSP-enzyme in the hybrid tilapia diet had significant effect on special growth rate(SGR) ,feed conversion rate(FCR) (P<0.05) ;(2) Digestibility of general apparent nutrients, protein, gross energy and some amino acid were also improved significantly (P<0.05) with NSP-enzyme, but the effects of enzyme supplement on the crude fat digestibility was not significant(p>0.05). (3)Crude protein contents of tilapia body composition was also significantly increased (P<0.05) with supplement of NSP-enzyme,the contents of crude ash and Ca and P was significantly reduced (P<0.05) in 0.04% group; (4) the tilapia diets with Supplement of NSP-enzyme had significantly increased serum total protein content(p>0.05); decreased TRIG, GLU, BUN of serum (P<0.05); increased T₃ and T₄ content of serum (P<0.05), had not affect insulin content.Exp.3 was conducted to study the effect of temperature and pH value on the activity of protease and amylase from hybrid tilapia.The result showed that the protease activity of intestine is much higher than that of liver. For protease, the optimum temperature was 55℃, while the optimum pH was 8.0.The change of temperature had no significant effect on the amylase activity of liver and intestine. In general, the optimum temperature was 40℃, while the optimum pH was 5.8-6.2 for the amylase activity.Exp.4 was conducted to study the effects of NSP-enzyme on avtivities of protease and amylase from tilapia.Hybrid tilapia was employed to study the effect of non-starch polysaachride enzyme (0.01%,0.02%,0.04% of diets)on activity of protease and amylase of different digestive organs and different time which including before feeding and 1, 3, 5h after feeding. The result showed that: (1) The activity of protease was gradually increased according to the order of liver-pancreas, stomach, and intestines; (2) the protease activity of liver-pancreas and stomach of 0.04% enzyme supplementation group was significant higher than that of control group (P<0.05) ;(3) The effect of NSP-enzyme on the protease activity of front intestine was irregular, and in general, the activity of 0.01% enzyme supplementation group was more higher than other group; (4) In all collecting time point ,except for 5h after feeding, the protease activity of middle-rear intestine of 0.01% enzyme supplementation group was significant higher than that of control group (P<0.05); (5) The amylase activity of front and middle-rear intestines increased with supplement of NSP-enzyme in a certain extent.Exp. 5 was conducted to to understand the regulation of activity and gene expression for pancreatic -liver amylase by utilization of NSP-enzyme. In this study, we obtained partial clones of tilapia cDNAs coding for alpha-amylase. we analyzed the activity and gene expressions of these enzymes amylase in pancreatic-liver of tilapia at Oh before feeding and 5h after feeding with (0.01%,0.02%,0.04%) or without NSP-enzyme. In a study of nutritional regulation, Our data show that levels of activity and mRNA of pancreatic-liver amylase were lower markedly in fish fed with 0.04% NSP-enzyme than in fish of other groups at 5h and 24h after feeding. It is expressed that the activity and the gene expression of pancreatic-liver amylase was affected by NSP-enzyme with 0.04% high level and not affected by the low level. It is suggested from this study that supplementation with NSP-enzyme may suppresss the activity and gene expression of pancreatic-liver amylase with the large volume.Exp.6 was conducted to study the effect of NSP-enzyme on the quality of tilapia water.The results showed that the pH value of feeding water was improved, the data of NH3-NH/ was decreased significantly, and the dissoluble oxygen was increased with supplement of NSP-enzyme in tilapia diets(P<0.05).In conclusion, Supplement of NSP-enzyme in diets of tilapia and carp had significant effect on growth performance and nutrient digestibility; Crude protein, crude ash, Ca and P contents of tilapia body composition was effected with supplement of NSP-enzyme; The diet with supplement of NSP-enzyme had increased the water quality of tilapia;While the blood biochemical index and some hormone level of tilapia had been effected.Supplement of NSP-enzyme in tilapia diets had increased protease activity of liver-pancrea and stomach, amylase activity of front intestine and middle-rear intestine had been increased, the activity and the gene expression of pancreatic -liver amylase was affected by NSP-enzyme with high level and not affected by the low level. Supplementation with NSP-enzyme may suppresss the activity and gene expression of pancreatic-liver amylase with the large volume.