Effects Of Lycium Barbarum Polysaccharides On Intestinal Microflora,Immune Function And Expression Of Related Genes In Broilers

As a kind of immune enhancer with high quantity,high safety,no pollution,no residue,no drug resistance,polysaccharide has high application value in regulating livestock growth and improving immune effect,and it is the most suitable antibiotic.One of the alternatives is of great significance for the development of a green animal husbandry.Therefore,this test by blood biochemical indicators,total protein,albumin,triglycerides,total cholesterol,anti-Newcastle disease immunoglobulin IgA,IgG content and broiler cecal content composition and diversity analysis,as well as various tissues and organs The changes of IL-2 and IL-6 mRNA expression were investigated,and the regulation mechanism of scorpion polysaccharide on broiler immunity was discussed.In this experiment,150 AA broilers of 1 day old SPF were randomly divided into 5 treatment groups,3 replicates per treatment,and 10 chickens per replicate.The control group was fed a basal diet,and the experimental group was fed a test diet supplemented with 1 g/kg,3 g/kg,5 g/kg,and 10 g/kg in the basal diet.The test period was 42 days.At the age of 24 and 42 days of broiler chickens,2 chickens were randomly selected from each replicate and blood was collected from the wing veins.Three slaughter samples were randomly selected from each group,and the cecal contents of the broilers were taken for high-throughput sequencing.The thymus gland,spleen and bursa of Fabricius were taken,total RNA was extracted from each tissue,reverse transcription was performed,and the relative expression levels of IL-2 and IL-6 genes were detected by real-time fluorescent quantitative PCR.The results are as follows:(1)The addition of alfalfa polysaccharide had no significant effect on the total protein and albumin of blood physiological indexes of broilers,indicating that the addition of alfalfa polysaccharide had no adverse effect on blood biochemical indicators during the test period,and the safe dose range was large,which was suitable for the broiler diet..The content of triglyceride and total cholesterol in the polysaccharide group was lower than that in the control group,indicating that the ability of the polysaccharide group to improve the lipid metabolism of the broiler chicken and the metabolic function of the liver were enhanced,which may help to reduce the abdominal fat percentage.It helps the body to show higher potential in growth,slaughter,etc.The anti-Newcastle disease immunoglobulin IgA and IgG levels in the experimental group were higher than those in the control group,which increased the body humor immunity and increased the ability of animals to resist Newcastle disease.(2)In this experiment,Illumina-Hiseq PE250 high-throughput sequencing technology was used to sequence the cecal contents of 30 chickens into the 16 S rRNA V4 region.The OTUs were classified according to 97% similarity,and a total of 2217198 Tags were detected.2092737 effective Tags.In the study,at the level of the door,the dominant flora of the broiler's intestine mainly consisted of the thick-walled bacteria and the Bacteroides.At the genus level analysis,it was found that the proportion of Bacteroides and Faecalibacterium was higher.The Alpha index had higher population abundance,diversity and phylogenetic diversity index in the fourth group(10g/kg)in 21 days.The first group(1g/kg)in 42 days had a high abundance and diversity of the flora.The phylogenetic diversity group 3(5g/kg)was higher than the other three groups.Beta diversity analysis found that when the amount of polysaccharide added was 10g/kg,the cecal flora of broilers was the most different from the control group.(3)By detecting the relative expression levels of IL-2 gene and IL-6 gene in broiler chickens at 42 days of age,it was found that the expression levels of IL-2 in 142-day-old broilers were higher than those in the control group.The highest expression was expressed in the third group.In 242-day-old broilers,the expression levels of IL-6 in each experimental group were higher than those in the control group,and the expression in the third group was the highest.The above results indicate that sputum polysaccharide can promote the expression of IL-6 and IL-2 mRNA to a certain extent,and can increase the secretion capacity of IL-6 and IL-2,and enhance the immune function of the body.Under the conditions of this test,the suitable addition level of lycium polysaccharide is 5g/kg-10g/kg.