Study On The Preparation Methods Of Simulating Duck Small Intestine Fluid

The objective of this study was to simulate the digestive physiology environment of the intestinal of pekin duck.So it could be manufactured the standardizing intestinal digestive enzymogram and buffer of duck, and validated the effectiveness of in vitro digestive on Simulative Digestion System. Finally, a method of preparaing simulation duck small intestine fluid was hold. It could be provided the basis on simulating intestinal digestive rapid, and resolving the key problem of enzyme source for evaluating the nutritive value the feedstuff.The first part was investigated to study the effects of cannulation on digestibility of dry matter and metabolic energy of diets in ducks, which would provide a reference for whether cannulation can regard as the mass, representative method of collecting intestinal fluids. A systematic grouping design was adopted, main factor had2levels (cannulation, discannulation), secondary treatment factor was the repeating group in cannulation (of which cannulation ducks2sets, discannulation ducks2sets). Metabolism weight loss, endogenous excretory capacity, digestibility of dry matter, metabolic energy of diets was determined in those two factors. The results showed that weight loss significantly risen (P<0.05).The cannulation did not affect endogenous feces excretory capacity, feces energy content, endogenous energy excretory capacity (P>0.05); also did not affect the dry matter digestibility and metabolic energy of diets (P>0.05).In conclusion, cannulation may did not affect the basic metabolism and digestive metabolism in2diets.The second part was conducted to investigate the differences in feed digestibility treated with mimic intestinal fluid composed with amylase, trypsin, chymotrypsin, lipase and in vivo intestinal fluid, as well as the effect of other enzymes on feed digestibility in intestinal fluid, which would provide a reference for the method of simulating duck intestinal fluid.A single factor completely randomized design was adapted. The digestive enzymes composition of intestinal fluid included3treatments with4main digestive enzymes and other digestive enzymes in endogenous intestinal fluid,4main digestive enzymes and different other digestive enzymes in intestinal fluid dry powder+reagent enzymes, and4main digestive enzymes in reagent enzymes. In in vitro digestion, each treatment contained5replicates with1simulative digestive tube per replicate. The in virto dry matter and energy digestibility of corn, soybean meal, cottonseed meal, wheat bran and4diets were determined using3treatments of intestinal fluid. The results showed that the intestinal fluid treatment had significant effects on the dry matter and energy digestibility of feedstuff and diets (P﹤0.05). But the significant difference in digestibility of all feedstuffs and diets treated with3intestinal fluids was not in accordance. The dry matter and energy digestibility in the treatment of mimic intestinal fluid preparated by reagent enzyme was above86%in feedstuff and93%in diet of that in treatment of endogenous intestinal fluid. The dry matter and energy digestibility in the treatment of mimic intestinal fluid preparated by duck intestinal fluid dry powder+reagent enzyme was above100.09%-103.52%of that in treatment of endogenous intestinal fluid. In conclusion, the four digestive enzymes in endogenous intestinal fluid were the most important for organic matter digestion. There was only1.72%of relative error of in vitro digestibility from other digestive enzymes. The method for simulative intestinal fluid preparation was controlling4main digestive activities using intestinal fluid dry powder and reagent enzyme according to that of endogenous intestinal fluid.The third part was conducted to compare the hydrolysis dynamics difference between endogenous intestinal fluids and simulating intestinal fluids, to ensure if they had the same enzyme character, which would provide a reference for the method of simulating duck intestinal fluid. A single factor completely randomized design was adapted, endogenous intestinal fluid and intestinal fluid dry powder (the intestinal fluid given first part)+reagent enzyme included. There were3、6、9、12、15、18and21h simulating times. The dry matter and energy digestibility of corn and soybean meal were determined;each treatment contained5replicates with1simulative digestive tube per replicate. The results showed that there were no significant effects of the hydrolysis dynamics difference between endogenous intestinal fluids and artificial intestinal fluids in dry matter digestibility of corn at3h (P>0.05), significantly affected at6、9、12、15、18and21h (P﹤0.05). There were also no significant effects of energy digestibility of corn between6and12h (P>0.05), but significantly affected among3、9、15、18and21h(P<0.05);As to the soybean meal, there were no significant effects of dry matter digestibility at3、15、8and21h (P>0.05), but significantly affected at6、9and12h(P<0.05).There were also no significant effects of energy digestibility of soybean meal among3、18and21(P>0.05), but significantly affected among6、9、12and15h(P<0.05).No matter for the dry matter and energy digestibility of com and soybean meal, the simulated intestinal fluid could account for95.19%-99.77%of endogenous intestinal fluid on average. This indicate that the hydrolysis dynamics activity of enzyme can regard as one of the methods of feed nutrient biology valence evaluation, and the simulated intestinal fluid made from intestinal fluid dry powder have the same enzyme features with endogenous intestinal fluids.