Effect Of Astragalus Polysaccharides On Performance, Antioxidant Enzyme Activity, Immuntiy Enginery And Intestined Microflora Of Laying Hens

The trial was designed to observe the effect of diet supplemented with different levels of Astragalus polysaccharide(APS) on Performance,Antioxidant enzyme activity,Immuntiy enginery and Intestined Microflora of Laying Hens and discussed the role of mechanism which could provide theoretical basis for the application of APS on production of laying hens.Hy-line laying hens were randomly divided into 6 groups, with 4 replications per group and 60 hens per replication.The control group was fed with basal diets, and the testing group was fed with basic diets adding 50mg/kg,100mg/kg,150mg/kg, 200mg/kg,250mg/kg APS respectively. Pretest period was 7 days and experimental period was 8 weeks. The main results were showed as follows:1.Laying hens diet added with APS affected feed consumption,ratio of feed to egg and body weight gain. Ratio of feed to egg of groupâ…£were significantly lower than the control(P<0.01),while groupâ…¡was significantly lower than the control(P<0.05); Average daily feed consumption per bird, in all test groups was significantly lower than the control(P<0.05), but which in the groupâ…¢,â…£,â…¤was significantly lower than the control (P<0.01); the body weight gain of groupâ…¤was significantly higher (P<0.05 ); In addition, diets supplemented with APS could increase egg production rate to some extent, but the difference was not significant (P> 0.05).2.The diet added with APS significantly enhanced yolk color (P<0.01), and Yolk color of groupâ…¤which was 8 was the hightest. The test improved egg Haugh unit, but the difference was not significant (P>0.05); Eggshell thickness of groupâ…£,â…¤andâ…¥were gradually increased,but the diffence was not significant compareing with the control group (P>0.05); the average egg weight among the test groups was not different significantly (P>0.05); Yolk ratio of groupâ…£was significantly lower than the control (P<0.05).3.Groups added with APS increased serum SOD and GSH-Px activity increased in each test group and decreased serum MDA content obviously (P<0.05).The SOD and GSH-Px activity in eggs was increased and MDA content was decreased by adding APS, but the difference among groups was not significant in difference varying degrees than the control group (P>0.05). Significantly lower MDA content of eggs than the control group, the difference was not significant (P>0.05). 4.The groups added with APS decreased, serum total cholesterol and low density lipoprotein cholesterol, which in groupâ…£decreased largestly, but the difference between groupâ…£and the control was not significant (P>0.05). Level of triglycerides in groupâ…¡,â…¤was significantly lower than the control (P>0.05). Level of high-density lipoprotein cholesterol in the test group tended to increase, but was not significant compared with the control (P>0.05). APS could adjust the cholesterol content in eggs. In groupâ…¡,â…¤,â…¥, the triglyceride content was significantly lower than the control (P<0.05),and total cholesterol and low density lipoprotein cholesterol decreased,high-density lipoprotein cholesterol content increased,but the difference was not significant (P>0.05).5.APS had different effect on the apparent digestibility layers. Conparing withâ…¥group,â…¤group was significantly affected on the apparent digestibility of calcium (P>0.05). APS could improve the apparent digestibility of crude protein to some extent which in groupâ…¤was the best, but the different were not significantly(P>0.05). APS had the similar effect on the apparent digestibility of EE and phosphony,but differences among the groups were not significant (P>0.05).6.The laying hens diets added with different levels of APS could increase spleen quotiety in different degrees, and the group ofâ…¡,â…¢,â…£,â…¤were significantly higher than the control (P<0.05). In addition, APS had some effect on antibodies against Newcastle disease, which in the test was higher than in the control, but the difference was not significant (P>0.05).The lymph nodules of the cecal tonsil of test groupâ… was larger than the control, while the other test groups were smaller, which had larger number of lymphoid nodules of the cecal tonsil than the control.7.APS had effect on the intestinal flora. APS had effect on E.coil significantly and E.coli of groupâ…£was significantly lower than the control group. Lactic acid bacteria and Bifidobacteria of groupâ…¢were higher than the control, but the difference was not significant (P>0.05).