Effects of chicory water-soluble extract on egg-yolk cholesterol, gut microflora and performance of laying hens.

The present study was conducted to investigate the effects of chicory water-soluble extract(CWE)on performance,egg quality,gut microflora,serum and yolk cholesterol in laying hens.A total of 300 Brown Nick laying hens were divided randomly into 5 groups with 6 replicates of 10 hens each,and fed diets containing 0(control),0.5%(CWE0.5),1.0%(CWE1.0)and 1.5%(CWE1.5)chicory water-soluble extract,respectively,as well as 1.0% inulin(I1.0)during 4 weeks' trial.The results showed that there were no significant differences in laying rate,average egg weight,feed intake,feed/egg,cracked egg rate,yolk weight,eggshell thickness and Haugh unit compared with the control(P0.05).Supplementing diets with CWE or inulin significantly reduced cholesterol concentration(mg/g yolk)and total cholesterol content(mg/yolk)in egg-yolk(P0.05).Compared with control,atherogenic index in serum was reduced by CWE1.5(P0.05).Dietary CWE or inulin supplementation significantly reduced the number of E.coli and pH in caecum of laying hens(P0.05).Caecum Bifidobacteria counts were increased in CWE1.5 group and I1.0 group(P0.05).Egg-yolk cholesterol content and the number of E.coli were decreased linearly(r=-0.957 and r=-0.977,respectively,P0.05)in accordance with increasing of dietary CWE level.It could be concluded that the incorporation of CWE or inulin in laying hens' diets could reduce egg-yolk cholesterol and caecum harmful bacteria(E.coli)counts with no any negative effects on laying hens' performance and egg quality in this trial(P0.05).Therefore,the dietary supplementation of CWE or inulin might lead to the development of low-cholesterol eggs as demanded by health-conscious consumers.