Effects Of Trans-anisole On Immune Function And Nutrient Utilization Of SPF Chickens

In this study,trans-anisole(main active ingredient in star anise oil)was taken as the research object.Firstly,the mechanism of trans-anisole in SPF chickens was systematically studied through the study of growth performance and immune property.Then the effects of trans-anisole on the nutrient utilization rate of SPF chicken was studied through the metabolic test,and the economic benefit was evaluated.It provided a theoretical basis for the application of star anise oil(SAO)and trans-anthole in poultry production.Study on the effects of trans-anisole on the growth performance and immune property of escherichia coli infected SPF chickens:experiment using 320 SPF adult white leghorns(male,with similar body weights,P>0.05)that were randomly designed according to factor2�2 and divided into 4 treatments(Cont,E.coli,SAO,E.coli+SAO)with 8 replicates respectively.Cont group and E.coli group fed basic diet.SAO group and E.coli+SAO group were supplemented with 0.04%star anise oil on the base diet.The test lasted for 28 days,divided into the adaptation period(1-7 days)and the trail period(8-28 days).Birds in E.coli group and E.coli+SAO group were orally challenged with 1.0 mL escherichia coli(0.8-1.2�10~3 cfu/mL)and those in other groups were orally challenged with 1.0 mL sterile meat medium(every other day from day 17 to day 27)during the experiment.The results showed that:(1)escherichia coli and star anise oil had no interaction effect on ADFI and BW of test chickens(P>0.05):escherichia coli significantly reduced the BW in chicken(P<0.05).Supplementation of star anise oil had no significant effect on ADFI and BW(P>0.05).(2)escherichia coli and star anise oil had significant interaction effects on lymphocyte proliferation rate and the content of TC in serum of test chickens(P<0.05).The SAO group significantly increased the lymphocyte proliferation rate(P<0.05)and decreased the content of TC in serum(P<0.05)compared with the Cont group.(3)escherichia coli and star anise oil had significant interaction effects on the contents of IgA,IgG,IgM,IL-6 and IL-18 in serum of test chickens(P<0.05).The SAO group significantly increased the content of IgM in serum compared with the Cont group(P<0.05).After oral administration of escherichia coli,supplementation of star anise oil significantly reduced the contents of IgA,IgG,IL-6 and IL-18 in serum(P<0.05).(4)escherichia coli and star anise oil had significant interaction effects on expression levels of IL-18,IFN-?,TNF-?,COX2 and NF-?B at mRNA level and TNF-?and IGF2 at the protein level in the spleen of test chickens(P<0.05).The SAO group significantly down-regulated the expression levels of IL-18 at mRNA level and TNF-?and IGF2 at the protein level in the spleen compared with the Cont group(P<0.05).After oral administration of escherichia coli,supplementation of star anise oil significantly down-regulated expression levels of IL-18,IFN-?,TNF-?,COX2 and NF-?B at mRNA level and TNF-?and IGF2 at the protein level in the spleen(P<0.05).Efficacy and economic benefit evaluation of trans anisole in improving nutrient utilization of SPF chickens:experiment using 96 SPF adult white leghorns(male)of roughly the same weight that were randomly divided into 4 treatments with 8 replicates respectively.Treatment one was the control group and fed the basal diet.Treatment two,three,four were supplemented with 0.02%,0.04%and 0.06%star anise oil respectively on the basis of the control.The contents of trans-anthole in tested groups were 0.019%,0.037%and 0.056%respectively.Experiment selected 24 SPF adult white leghorns(male)as the endogenous blank control to calculate the true metabolic rate.The test lasted for 10 days(the adaptation period was 7 days and the trail period was 3 days),and used the total fecal urine method.The results showed that:the apparent and true utilization rate of GE and the apparent and true metabolic energy of experimental chickens increased linearly with the increase of star anise oil addition level(P<0.05),while the apparent utilization rates of CP increased conic with the increase of star anise oil addition level(P<0.05).Supplementation of star anise oil significantly affected the apparent and true utilization of valine,threonine and non-essential amino acids and the apparent utilization of methionine in birds(P<0.05).The apparent and true utilization rates of valine,isoleucine,glycine and alanine increased linearly and conic with the increase of the addition level(P<0.05),while the apparent and true utilization rates of threonine,methionine,serine and cysteine increased conic with the increase of the addition level(P<0.05).Compared with no star anise oil,adding 0.02%,0.04%and 0.06%star anise oil in the diet could increase the benefits of 22.70,3.62 and-16.93 yuan/ton respectively,after deducting the cost of adding star anise oil.From the above,trans-anisole(main active ingredient in star anise)could inhibit the activation of NF-?B pathways in the spleen,down-regulate the expression of relevant inflammatory genes at the mRNA level and the expression of TNF-?and IGF2 at the protein level,reduce the content of proinflammatory cytokines in serum and the lymphocyte proliferation rate,thereby enhancing the body's immunity and alleviating the damage caused by escherichia coli.The effects of star anise oil on nutrient utilization rate of SPF chickens had dose effects.Adding 0.02%and 0.04%star anise oil could improve nutrient utilization rate and increase economic benefits.It is of great significance to study the mechanism of immune function regulation in poultry and the application of star anise oil and trans-anisole in poultry production.