Evaluation Of Enzymatic Protein Peptide In Vitro And Its Application In Piglet Production

This experiment analyes the effect of enzymatic protein peptide on gastrointestinal digestive residue in weaned piglets by using in vitro digestion experiment,and study on the effect of enzymatic protein peptide on the growth indicators,serum biochemical indicators,apparent digestibility of nutrients and fecal indicators of weaning piglets through feeding experiment.This experiment provide the effective basis for searching for the optimum addition of enzymatic protein peptide in the diet of weaned piglets and predicting in vivo digestibility by in vitro digestibility.Test one:In vitro digestion test of enzymatic protein peptide.Simulating gastric and intestinal juice environment of 21-day-old weaned piglets for digestive juice p H value,enzyme concentration,digestive temperature and time and other indicators.Putting piglet diets supplemented with 0?2%?4%?6% and 8%enzymatic protein peptide into the set digestive juice respectively,then determination of the p H value of the gastric and intestinal juices after digestion,the small intestine chymus of dry matter and crude protein digestibility and the content of volatile fatty acids.Test two:Effects of enzymatic protein peptide on growth indicators,serum biochemical indicators,apparent digestibility of nutrients and fecal indicators of piglets.Design of single-factor random trials.One hundred and fifty piglets(Duroc×Landrace×white)are randomly selected and allotted to five treatments in this experiment,there are 5 replicates in each group.The control group piglets fed the basal diet,the experimental group piglets' ration respectively added2%,4%,6%,8% enzymatic protein peptide,and the trial period is 28 days.The results are as follows:1.In vitro digestion test,the digestive juice p H of 21-day-old weaned piglets simulated in vitro is not significantly affected by enzymatic protein peptide(P>0.05),but the digestibility of dry matter and the content of volatile fatty acids in small intestine digestive residue of piglets are significantly increased(P<0.05),the digestibility of crude protein is significantly improved in 8% enzymatic protein peptide group.2.In piglets feeding test,the growth performance of weaned piglets can be improved by adding enzymatic protein peptide in diet.The ADFI and ADG of piglets increase significantly(P<0.01),but the F/G(P<0.05)and diarrhea frequency(P<0.01)decrease significantly by adding enzymatic protein peptide,6% and 8% enzymatic protein peptide group have the best effect.3.The immune performance of weaned piglets can be enhanced by adding enzymatic protein peptide in die.The content of serum Ig G and Ig M of piglets increase significantly(P<0.01),and the content of blood sugar of piglets increase significantly too(P<0.01)by adding enzymatic protein peptide,helping to reduce stress.4.The serum protein level of weaned piglets can be increased by adding enzymatic protein peptide in diet.The content of serum BUN in piglets decrease significantly with the increase of enzymatic protein peptide(P<0.01);the enzymatic protein peptide also increase significantly the content of serum TP?ALB and GLB of piglets(P<0.01),6% enzymatic protein peptide group have the best effect.In addition,enzymatic protein peptide have no significant effect on serum T-CHO ?TG?ALT and AST levels in piglets(P>0.05).5.The digestion and absorption of protein of weaned piglets can be promoted by adding enzymatic protein peptide in diet.The digestibility of dry matter(P<0.05)and crude protein(P<0.01)in piglets are increase significantly,but the digestibility of crude fat and calcium and phosphorus have no significant impact(P>0.05).6.The intestinal environment of weaned piglets can be improved by adding enzymatic protein peptide in diet,the content of lactate,acetic acid and propionic acid in piglet manure are increase significantly(P<0.01).Enzymatic protein peptide can also regulate the flora structure in piglet manure,the proportion of lactic acid bacteria in feces increases significantly(P<0.01),and proportion of E.coli decreasessignificantly(P<0.05).The dominant bacteria in feces are Firmicutes at phylum level,and Clostridium sensu stricto at genus level.7.The results of in vitro digestion simulation test and feeding test are in strong correlation.In vitro and in vivo dry matter digestibility(r = 0.906,P < 0.01)and crude protein digestibility(r = 0.864,P < 0.01)are significantly correlation.In conclusion,enzymatic protein peptide can improve the growth performance and immune performance of weaned piglets,improve protein digestibility,maintain intestinal health,regulate the flora structure in feces,and the optimum amount of enzymatic protein peptide in the diet of weaned piglets is6%-8%.