Effects Of Organic Acid And Essential Oil On Growth Performance And Intestinal Health In Weaned Piglets

Organic acid and essential oil are both alternatives to antibiotics,which is safe and environment-friendly.Dietary supplementation with organic acids has been hypothesized to improve growth performance by lowering gastrointestinal p H and subsequent modification of the intestinal microflora;essential oil exerts beneficial effects on animal growth performance and intestinal health in piglets due to their antimicrobial properties,besides,antioxidant properties and immunity ability also can be influenced.Therefore,the aim of this present study was to explore the optimal proportion of organic acid with essential oil compound,made it into microcapsules;through animal experiments to explore the effect of the microcapsules on growth performance,immunity and fecal flora of weaned piglets,providing a new idea for improving the bacteriostatic ability of feed,regulating intestinal flora and improving intestinal immunity of animals.1.The antibacterial effect of essential oil and organic acid in virtoThe Oxford cup method was used on essential oil(thyme phenol,cinnamaldehyde,vanillin)and organic acid(citric acid,benzoic acid and sorbic acid),which was aimed to find the best proportion of the compound essential oil and organic acid.The results showed that the best proportion of thymol and cinnamaldehyde was 1:3.The antimicrobial effect of essential oil and citric acid in the ratio of 1 to 3 is still very sensitive to Escherichia coli and staphylococcus aureus.The results suggested that the compound of essential oil and citric acid can be used in the following animal experiment.2.The effect of essential oil and organic acid on bacterial structureTransmission electron microscope was used to observe the effect of essential oil and organic acid on structure of Escherichia coli and Staphylococcus aureus.The results showed that the Staphylococcus aureus in the control group was round,the structure was intact,the cell wall was smooth,and the electron cloud distribution in the bacteria was even;After 8 h of cinnamaldehyde treatment,the plasmolysis of Staphylococcus aureus was isolated,bacterial cell wall was dissolved,contents were overspill,and the bacterial electron cloud distribution was not uniform;After 8 h treatment with citric acid,the plasmolysis of Staphylococcus aureus was isolated,the contents were spilt,the bacterial cell wall was dissolved,the bacterial content was missing,and the distribution of bacterial electron cloud was not evenly.With the effect of cinnamaldehyde and citric acid,the morphological change of E.coli is similar to that of S.aureus.The results suggested that both essential oil and organic acid have effect on the structure of E.coli and S.aureus to achieve the bacteriostatic effect.3.The effect of compound organic acid and essential oil on the growth performance,fecal volatile fatty acids,immunity and antioxidation function in weaned pigletsThree hundred weaned piglets were randomly divided into 3 treatments(control group,antibiotics group and compound organic acid and essential oil group),10 replicates for each treatment and 10 piglets per replicate.Data was collected after 28 day’s trial.The results indicated that compound essential oil and organic acid group and antibiotic group significantly increased the final weight,average daily weight gain(P<0.05),when compared with the control group.In day 28,isovalic acid in compound organic acid and essential oil group was significantly higher than that in the other two group,the propionic acid was on increase.In day 28,the concentration of T-SOD and C4 in compound organic acid and essential oil group and antibiotics group was significantly increased than that in the control group(P<0.05).The results suggested that the growth performance,the volatile fatty acids,the immunity and antioxidation ability can be influenced by compound organic acid and essential oil in some way.4.The Effect of compound organic acid and essential oil on flora in weaned pigletsSamples of weaned pig feces were collected on day 14 and 28.According to rarefaction curve and rank abundance,800 bp OTUs was tested.According the diversity index,there are no significant different among three groups.The weaned piglets’ cecum contains 80 % of Firmicutes in the phylum level,there are no significant difference among three groups;Lactobacillus(about 20 %)in the genus level,which was significantly increased in compound organic acid and essential oil group than other two groups;in the species level,Lactobacillus salivarius in compound organic acid and essential oil group was significantly increased on day 14 than that of control group and antibiotics group,Lactobacillus mucosae in compound organic acid and essential oil group was significantly increased on day 28 than that of other two group.The results suggested that the diversity of fecal flora of weanling piglets changed with the addition of compound organic acid and essential oil.