The Effects Of Exogenous Trypsin On Growth Performance,nutrient Digestion And Absorption And Intestinal Microorganism Of Piglets

Pancreatin is secreted by pancreas,mainly including trypsin,pancreatic lipase and pancreatic amylase,which plays an important role in improving nutrient digestion and absorption and promoting growth performance.After weaning,the secretion of trypsin decreased significantly for a period of time,which affected the utilization of nutrients.The addition of exogenous trypsin preparation is expected to alleviate this situation.At present,trypsin has been approved to be used in dogs and cats in China,but there is a lack of research in pigs.Therefore,this study explored the effects of trypsin on growth performance,nutrient apparent digestibility,serum biochemical indexes,antioxidant and immune functions,small intestine morphology,endogenous enzyme activity,immune function and other indicators of piglets The effects of endogenous enzymes and jejunal nutrient transporter gene expression and intestinal microorganisms provide theoretical basis and technical support for the development of pancreatin as a new feed additive.180 40 day old Duroc Landrace piglets were randomly divided into 3 groups with 3 replicates in each group and 20 pigs in each replicate.The corresponding diets of each group were as follows: 1)basic diet;2)The basal diet was supplemented with250 mg / kg trypsin;3)The basal diet was supplemented with 500 mg / kg trypsin.The test period was 45 days.The main results are as follows1 The effects of pancreatin on growth performance,apparent digestibility,serum and lipid,antioxidant and immune function of piglets.1.1 The effect of pancreatin on growth performance and apparent digestibility of pigletsCompared with the control group,adding 500 mg / kg trypsin could significantly increase the average daily gain of piglets(P < 0.05),improve the feed intake and reduce the feed to weight ratio(P > 0.05);At the same time,compared with the control group,the addition of 500 mg / kg trypsin significantly improved the apparent digestibility of crude protein and crude fat(P < 0.05).The addition of 250 mg / kg trypsin also had a certain effect,but there was no significant difference compared with the control group.1.2 The effect of pancreatin on serum and blood lipid indexes of pigletsCompared with the control group,the addition of 500 mg / kg trypsin significantly increased the content of total protein and albumin in serum(P < 0.05),in addition,significantly increased the content of high-density lipoprotein(P < 0.05),significantly reduced the content of total cholesterol in serum(P < 0.05).The addition of 250 mg / kg pancreatin significantly improved the content of serum albumin(P <0.05),and significantly decreased the content of serum low density lipoprotein and total cholesterol(P < 0.05).There were no significant differences in blood glucose and serum globulin content among the experimental groups.1.3 The effect of pancreatin on antioxidant and immune capacity of pigletsCompared with the control group,the supplementation of 250 mg / kg and 500 mg / kg trypsin significantly reduced the content of malondialdehyde(MDA)in serum of piglets(P < 0.05).Compared with the control group,the activities of total antioxidant capacity(T-AOC),catalase(CAT),superoxide dismutase(SOD)and glutathione peroxidase(GSH PX)in serum of piglets fed with 500 mg / kg trypsin increased(P ﹤ 0.05),but the differences were not significant.In terms of immune function,the supplementation of 500 mg / kg trypsin significantly increased the content of Ig A and Ig G in serum of piglets(P < 0.05),and the content of Ig M in serum of piglets showed an upward trend(P > 0.05).There was no significant difference between 250 mg / kg trypsin group and control group.The addition of 500 mg / kg trypsin improved the antioxidant and immune function of piglets to a certain extent.2 The effects of pancreatin on intestinal morphology,digestive enzyme activity,nutrient transporter gene expression and intestinal microorganism in piglets.2.1 The effect of pancreatin on digestive enzyme activity of pigletsCompared with the control group,the addition of 500 mg / kg trypsin had a certain improvement effect on the morphology of each segment of the small intestine,in which the effect of ileum was the most significant,and the villus height and villus to cryptic ratio of ileum were significantly improved(P < 0.05).In addition,the addition of trypsin improved the endogenous enzyme activity of piglets: the addition of 500 mg / kg trypsin in the diet significantly increased the trypsin activity in jejunum contents of piglets(P < 0.05),and the protease activity in duodenum mucosa also had a certain upward trend(P ﹤ 0.05);The activity of pancreatic lipase in pancreas,duodenum mucosa,duodenum,jejunum and ileum was significantly increased(P < 0.05);The activity of pancreatic amylase in pancreas and the activity of pancreatic amylase in duodenal mucosa and its contents were also significantly increased(P < 0.05).2.2 The effect of pancreatin on gene expression of trypsin and jejunal nutrient transporter in pigletsThe addition of 500 mg / kg trypsin significantly increased the gene expression of nutrient transporters in jejunum.Compared with the control group,adding 500 mg /kg trypsin could significantly up regulate the m RNA expression of oligopeptide transporter(Pep T1),excitatory amino acid transporter-1(EAAC1),cationic amino acid transporter-1(CAT1),glucose transporter(GLUT2)and fatty acid transporter-4(FATP4)in jejunum of piglets(P < 0.05).2.3 The effect of pancreatin on intestinal microflora in pigletsThe addition of 500 mg / kg trypsin had no significant effect on the species richness and diversity of intestinal microflora in piglets,and did not significantly change the structure of microflora,but increased the relative abundance of lactic acid bacteria in the colon.In addition,the addition of 500 mg / kg trypsin increased the functional abundance of colonic microorganisms involved in genetic information processing and cell signal transduction,and decreased the abundance of colonic microorganisms involved in metabolic pathways.In conclusion,500 mg / kg pancreatin can significantly improve the daily gain and Nutrient Apparent Digestibility of piglets,improve the antioxidant and immune capacity of piglets,significantly increase the intestinal endogenous enzyme activity,significantly up regulate the gene expression of pancreatic trypsin and jejunal nutrient transporter,and increase the relative abundance of beneficial bacteria Lactobacillus in colon.This study provides theoretical basis and technical support for the application of trypsin in piglets.