Effects Of The Combination Of Essential Oils And Tributyrin On Performance And Intestinal Microflora Of Weaned Piglets

Weaning stress often damages the digestive tract,inhibits the growth of piglets,and leads of economic loss of pig production.In this study,the combination of tributyrin and essential oils was optimized for improving their bactericidal capatibility.The aim of this study was to determine the effects of dietary inclusion of the combination of tributyrin with oregano or methyl salicylate to diet as a substitute antibiotics on gut health and microbiota of piglets,which can provide new ideas for the application of antibiotic substitutes in livestock and poultry production.1.E stablishment of antibacterial method for compatibility of tributyrin with essential oil and screening of compatibilityThe tube culture and coating culture was used to determine the minimum inhibitory concentration of the combination of tributyrin and essential oils at different ratio.The results showed that 70%of tributyrin combined with 30%oregano oil or 30%methyl salicylate,which had the best antibacterial effect against Escherichia coli,Salmonella and Slaphylococcus aureus.2.The effects of dietary inclusion of the combination of tributyrin with essential oil to substitute antibiotics on growth performance and serum characteristics of weaned pig.Total 48 weaned crossbred piglets(Duroc × Large White × Landrace,8.79±0.97 kg,26± 1 d)were randomly allocated to 4 experimental groups(12 piglets/treatment distributed in three pens)fed with one of following diets for 4 weeks:the basal diet,which were formulated as the control diet without antibiotic additives(Con):the control plus antibiotics diet(AB);the control plus 0.6 g/kg oregano and 1.4 g/kg tributyrin diet(OT);and the control plus 0.6 g/kg methyl salicylate and 1.4 g/kg tributyrin diet(MT).The test period was 35 days.Upon termination of the feeding trial,blood was collected from the anterior vena cava of all piglets for serum indicators analyses.6 pigs(3 barrow and 3 gilt)were selected randomly from each replicate of the control group,AB group OT group and MT group and were slaughtered after a 24 hour fast,and the intestinal contents and intestinal mucosa were collected for intestinal microflora and morphology analysis.The results showed that:1)The differences in daily weight gain,feed intake and daily weight gain were not significant(P>0.05).2)The blood general health parameters which contains total protein,albumin,glucose,BUN,AST/GOT,ALT/GPT,ALP,SOD,MDA,GSH-PX,T-AOC were not significant(P>0.05).3.The effects of dietary inclusion of the combination of tributyrin with essential oil to substitute antibiotics on gut microbiota and metabolomic of weaned pig.The samples were form the animal feeding trial mentioned above.1)There was no significant difference in stomach pH,duodenal pH,colon pH and cecal pH between all groups(P>0.05).Compared with the Con group,the OT group significantly increased the pH of the jejunal contents of the weaned piglets(P<0.05),and the MT group significantly increased the pH of the ileal contents of the weaned piglets(P<0.05).2)Compared with the Con group,the OT group significantly increased the duodenal villus length and jejunum’s villus height/crypt depth ratio in weaned piglets(P<0.01),and the MT group significantly increased the weaned pig’s duodenum Intestinal and jejunal villus length,jejunum villus height/crypt depth ratio(P<0.01),which significantly increased duodenal villus height/crypt depth ratio(P<0.05).Compared with the AB group,MT significantly increased the length of jejunum villi(P<0.01)and significantly reduced the depth of ileal crypt(P<0.01).3)The contents of acetic acid,propionic acid,isobutyric acid,butyric acid,isovaleric acid and valeric acid in the colon contents of weaned piglets were not significantly different(P>0.05).Compared with the Con group and the AB group,the MT group had an increasing trend of short-chain fatty acid content.4)High-throughput sequencing of 16S rRNA and fecal microbiota counts showed that the number of Escherichia coli was decreased in the MT group(P<0.01),while the number of lactic acid bacteria in the OT group was increased(P<0.01).Compared with the Con and AB groups,OT and MT increased(P<0.01)the relative abundance of the Firmicutes at the door level.Compared with Con,MT caused a relatively low abundance of Proteohacteria(P<0.05).At the genus level,OT and MT resulted in lower relative abundances of Actinobacillus and Escherichia coli compared to Con(P<0.01).5)GC-MS metabolomic results of ileal contents of weaned piglets showed that metabolomic analysis of intestinal contents showed 6,8 and 8 major metabolites in the AB,OT and MT groups compared to Con group(VIP>1.5,P<0.05).In conclusion,as a substitute for antibiotics the inclusion of the combination of tributyrin with either oregano or methyl salicylate to the diets of weaned piglets improved the intestinal morphological structure and altered intestinal microbiota and metabolites,which were beneficial to the animal health.