Effects Of Dihydromyricetin On Growth Performance And Immune Function Of Chicks

In recent years,due to the discovery of multi-drug-resistant bacteria,my country has issued a "anti-anti-anti" decree.Therefore,looking for green feed additives with low toxic and side effects is of great significance to improving animal performance and immunity,and protecting animal health.Dihydromyricetin(DHM)is a natural plant extract in Tengcha.It has many pharmacological activities such as antioxidant,antibacterial,and anti-inflammatory.It has the advantages of clear structure,wide source,mature extraction and separation technology,and high content of ingredients.There will be a good development trend in animal husbandry.In this experiment,Hailan white chicks were used to add Dihydromyricetin to the feed to study the effect on the growth and immunity of the chicks,so as to provide a reference for the rational development of Dihydromyricetin and its application in aquaculture production.In this experiment,150 7-day-old chicks were randomly divided into a control group and a treatment group.The control group was given a basic diet,and the treatment group was given0.025%,0.05%,0.1%,and 0.2% DHM for 35 consecutive days.Record feed intake and growth status every day,weigh weekly,calculate daily feed intake,daily weight gain,feed-to-weight ratio and survival rate.Six chicks were randomly selected from each group at 14,21,28,35,and 42 days of age.Blood was collected from the heart,the serum was separated,and the thymus,spleen and bursa of Fabricius were removed and weighed,and the organ index was calculated.The ELISA method was used to determine the serum Ig G,C3 and C4 contents at 21,28,35,and 42 days of age,and analyze the effect of DHM on the immune organ index,serum immunoglobulin and complement content of chicks,and select 42-day old chicks for further study based on the test results.Fluorescence quantitative PCR was used to detect the mRNA expression of cytokines(IL-2,IL-4,IFN-γ and TNF-α)in the spleen,thymus and bursa of fabrics in 42-day-old chicks.The spleen,thymus and bursa of fabric of 42-day-old chicks were observed by HE staining method.The test results are as follows:(1)The effect of DHM on the growth performance of chicks: Compared with the control group,the average body weight of the chicks in each treatment group increased,and the average body weight of the 0.1% and 0.2% DHM groups increased significantly at the age of 42 days(p<0.05);The average daily feed intake of the 0.1% DHM group increased significantly at the age of 14-21 days(p<0.05),and the average daily feed intake of the 0.05%,0.1% and 0.2% DHM group was significantly or extremely significant at the age of 28-35 days Increase(p<0.05 or p<0.01);0.05,0.1% and 0.2% DHM group in the 35-42 days of age,the average daily gain was significantly or extremely significantly increased(p<0.05 or p<0.01),and the meat-to-feed ratio The increase was significant(p<0.05);DHM had no effect on the survival rate of chicks.It shows that DHM can increase the average weight,average daily feed intake,average daily gain and meat feed ratio of chicks.(2)The effect of DHM on the immune function of chicks: Compared with the control group,the thymus index of the 0.2% DHM group was significantly increased at 35 and 42 days of age(p<0.05);the 0.2% DHM group was at 28,35 and 42 days The spleen index increased significantly at age(p<0.05),and the spleen index increased significantly at 42 days in the 0.05% and 0.1%DHM groups(p<0.05);the 0.1% and 0.2% DHM groups increased significantly at 14 days of age.The bursa index increased significantly(p<0.05),and the 0.2% DHM group showed a very significant increase at 28 days of age(p<0.01).Compared with the control group,serum Ig G levels in the 0.05%,0.1% and 0.2% DHM groups increased significantly or extremely significantly at 35 and 42 days of age(p<0.05 or p<0.01);the 0.1% and 0.2% DHM groups The serum C3 content increased significantly or extremely significantly at 21 days of age(p<0.05 or p<0.01),and the serum C3 content increased extremely significantly at 28,35,and 42 days of age(p <0.01);the0.025% DHM group was in Serum C4 levels increased significantly at 21 days of age(p<0.01),and serum C4 levels increased significantly or significantly at 21,28,35,and 42 days of age in the0.05%,0.1%,and 0.2% DHM groups(0.05 or p<0.01).The above results show that DHM can improve the index of immune organs of chicks and increase the content of Ig G,C3 and C4 in the serum of chicks.(3)The effect of DHM on the expression of cytokines in the thymus,spleen and bursa of fabric in chickens: Compared with the control group,the expression of TNF-α,INF-γ and IL-4mRNA in the thymus of the 0.025% DHM group increased significantly(p<0.01),the expression of thymus INF-γ mRNA in the 0.05% DHM group increased significantly(p<0.01);the spleen IFN-γ mRNA expression in the 0.025% DHM group increased significantly(p<0.01),0.1% The expression of TNF-α and IL-2 mRNA in the spleen of the DHM group increased significantly(p<0.01),and the expression of IFN-γ and IL-4 mRNA in the spleen of the DHM group was significantly or extremely decreased(p<0.05 or p<0.01);the expression of TNF-α and IFN-γmRNA in the bursa of Fabricius in the 0.025% DHM group increased significantly(p<0.01),and the expression of IL-4 and IL-2 mRNA in the bursa of Fabricius was in each administration There was a significant or extremely significant decrease in the group(p<0.05 or p<0.01).The above results indicate that DHM can promote the expression of TNF-α,IFN-γ,IL-4 and IL-2 mRNA in the thymus,spleen and bursa of fabric in chickens.(4)The effect of DHM on the histomorphology of the thymus,spleen and bursa of fabric in chickens: the thymus cortex in each treatment group was thickened,the color of the medulla became darker and denser;the thymus lobules in the 0.2% DHM group were clearer,and the number of thymic corpuscles Significantly increased.In the 0.025%,0.05%,and 0.1% DHM groups,the red and white marrow of the spleen were clearly demarcated,the white marrow increased,and the area of the marrow increased;in the 0.2% DHM group,the lymphatics around the arteries were clear,and the splenic corpuscles increased.The lymphoid follicles in each treatment group became larger and longer,and the medulla area increased;the interval between follicles in the 0.1% and 0.2% DHM groups became smaller,and the lymphocytes were arranged more densely.From the above results,it can be seen that DHM can promote the development of the immune organs of the chicks and make the internal tissue structure more compact.The above research results show that adding Dihydromyricetin to chicken feed can promote the increase of body weight,daily feed intake and meat ratio;it can improve the index and function of immune organs,increase the content of Ig G,C3 and C4 in serum,and regulate the thymus of chickens.The expression of cytokines in the spleen and bursa of fabrics promotes the development of thymus,spleen and bursa of fabrics.In summary,it can be seen that Dihydromyricetin can improve the growth performance of chicks and enhance their immune function,and the dietary supplement with 0.2% Dihydromyricetin has a better effect.