| Recently,the food safety is a hotspot of public issue.Exploring the replaceable agents of antibiotics in breeding of chicken could reduce the usage of antibiotics and further improve the safety of the chicken products.In this study,we set the extract of Australia tea tree as target to identify its antibacterial activity in common susceptible bacterial and potential regulating on immunity of chicken,which will be the theoretical basis of finding the replaceable regents for antibiotics in breeding chickes.Object1.Verify the antibacterial activity of Australia tea tree extract in chicken susceptible bacteria.We diluted the Australia tea tree extract concentration to 1x,1/10 x and 1/100 x,then tested its antibacterial activity on Escherichia coli,Bacillus,Salmonella,Staphylococcus Aureus standard bacterial and etc,Ampicillin,Amoxicillin,Florfenicol,Ceftriaxone,Azithromycin,Azithromycin,and Neomycin were set as positive controls.The results showed that Australia tea tree extract has positive effect on all four chicken source pathogenic bacteria.Additionally,the activity on Staphylococcus Aureus,and Salmonella were better than Pasteurella,and E.coli,and the bacteriostatic ring were15.80 mm,15.16 mm,14.80 mm and 14.06 mm,respectively.Even though the Australia tea tree extracts showed lower antibacterial activity on four chicken source pathogenic bacteria,the extract has higher efficiency than commonly used antibiotics Amoxicillin and Enrofloxacin in preventing chicken disease in drug resistance aspect.Furthermore,low concentration(1/100)of Australia tea tree extract still has potential antibacterial effect on four chicken original pathogenic bacteria.2.Investigate the effect of Australia tea tree extract on chicken immunityWe equalized 120 one day birth Guangxi Yellow chickens Gallus Guangxi Yellow Chicken into three group as experiment group,positive antibiotics group and negative control group.We sacrificed the chickens at 2 weeks,4 weeks and 6 weeks and separated the serum and lymphocytes to measure the concentration of lysozyme,IgG and ratio of CD4+/CD8+.On the other hand,we also evaluated the development of thymus,Bursa of Fabricius and spleen.The concentration of lysozyme was 19.31 U/mL?19.69 U/mL?36.29U/mL extra higher and the ratio of CD4+/CD8+ was improved by 6 percent,9 percent and16 percent,respectively,compared with negative control group at above mentioned timepoint.These data indicated that Australia tea tree extract has positive effect on chicken immunity.3.Identify the effect of Australia tea tree extract on chicken developmentWe equalized 400 one day birth Guangxi Yellow chickens into four groups as extract group I,extract group II,positive antibiotics group,and negative control group.During the45 days breeding,we monitored the incidence rate,mortality,feed intake,weight and meat ratio.The data elucidated that extract group II could notably increase the chicken weight more than 90 g,and 100 g feed intake,while decrease the meat ratio nine percent compared to antibiotics group.Additionally,the extract group chicken seems much healthy than other groups,the incidence rate and mortality showed no difference with antibiotics group,which is much lower than negative control group.ConclusionOur data showed that Australia tea tree extract could markedly inhibit the common chicken original pathogenic bacteria and improve the immunity and productivity of the chicken during development,which comes the conclusion that Australia tea tree extract has great potential application in chicken breeding. |
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