Studies On The Solid State Fermentation Technology Of Astragalus Using Aspergillus Niger And Its Application In Laying Hens

In this experiment,Aspergillus niger was used to ferment with Astragalus in the form of solid state fermentation.Single factor test and orthogonal test were used to determine the feasibility of the experiment and the optimal fermentation process.The activity of cellulase and amylase and the yield of Astragalus polysaccharide were determined after fermentation,meanwhile,the variation of different active components was analyzed.Solid fermentation preparation was added to laying hens diet to observe its application effect in laying hens production,and production performance and serum antioxidant indexes of laying hens were determined as well.The main results are as follows:(1)The optimal production process of solid state fermentation of Astragalus with Aspergillus niger:single factor experiment was used to explore the effects of different temperature,inoculations,water content and fermentation time on cellulose,amylase and Astragalus polysaccharide.On the basis of the single factor test,orthogonal test was used to determine the optimal fermentation process.The result discovered that the optimal fermentation condition for cellulase production is 37?,1%inoculation volume,45%water content of culture medium,and fermentation time was 9d.In this condition,the cellulase activity could reach 82.26U/g.The optimum condition for amylase production is 28?,1%inoculation volume,45%water content of culture medium,and fermentation time was 9d.To some extent,the change rule of Astragalus polysaccharide was opposite to that of the two enzymes,which may be that Astragalus polysaccharide was utilized or converted into other substances by Aspergillus Niger during fermentation.(2)The application results of fermented Astragalus preparation in laying hens:A total of seventy two 280 days of age laying hens were selected and randomly divided into four groups,which were fed basic diet,basic diet+2‰ Astragalus,basic diet+2‰Aspergillus Niger and basic diet+2‰ fermented Astragalus respectively.During the 1-14 days of the experiment,there was no significant difference in laying rate and feed-egg ratio between the fermented Astragalus group and other control groups(P>0.05).During the 15-28 days of the experiment,the egg laying rate of the fermented Astragalus group was as high as 96.73%,which increased by 18.79%,9.21%and 12.85%respectively compared with the blank group,the Astragalus group and Aspergillus niger group,and the difference is significant(P<0.05).Meanwhile,the feed-egg ratio of the fermented Astragalus group dropped to 1.83,which dropped by 19.71%,9.49%and 20.62%respectively compared with the blank group,the Astragalus group and the Aspergillus niger group,and the difference is significant(P<0.05).In terms of the serum antioxidant index,on the 14th day of the experiment,the activity of T-AOC in serum of laying hens of the fermented Astragalus group can reach 4.15 U·mL-1,which significantly higher than other three groups(P<0.05).The content of the MDA is 0.49 nmol·mL-1,which was significantly reduced compared with blank group and Aspergillus niger group(P<0.05).However,there was no significant difference compared with Astragalus group(P>0.05).On the 28th day of the experiment,the activity of CAT,GSH-Px and SOD in serum of laying hens of the fermented Astragalus group was 10.43 U·mL-1 16.93 U·mL-1 and 123.83 U·mL-1,respectively.It was significantly improved compared with the other three groups(P<0.05).The results indicate that after Astragalus was fermented by Aspergillus niger,the activities of cellulase and amylase were increased,but the yield of Astragalus polysaccharide was decreased.The Aspergillus niger fermented Astragalus preparation can improve the production performance and serum antioxidant status of laying hens.It can be used as a new kind of feed additive.