Study On The Process Optimization And Microbial Diversity Of A Fermented Feed

With the development of society,the transformation of breeding methods and the improvement of technology,people are facing problems such as drug resistance of various pathogenic bacteria and the large amount of Antibiotics remaining in the body.Therefore,animal husbandry urgently needs to find a green,non-toxic feed,and microbial fermented feed just meets people’s current needs.In this experiment,first of all,from the perspective of improving feed utilization,the three starters of Kefir,Bacillus natto and Saccharomyces cerevisiae were respectively fermented feed with the urease content as the main index for the effect of raw materials.It is also measured for nutritional indicators,in vitro antioxidant capacity and pH.The measurement results show that the three starters have a significant effect of reducing the anti-nutrition factor urease and the content of total protein,total sugar and the capacity of antioxidant have also been increased.Therefore,the follow-up experiment adopts the mixed fermentation method of the above three species.Next,it is considered that the oxygen demand of Saccharomyces cerevisiae,Lactic acid bacteria,and Bacillus natto is different during the fermentation process.According to the understanding of the factory fermentation,the fermentation bag is generally opened and the fermentation bag is sealed for a period of time.Because the phenolic substances in the fermented feed can clear the free radicals in the body,it can delay or prevent the active substances in the feed from being oxidized by free radicals with strong oxidizing properties,thereby enhancing the stability of the nutrients in the fermented feed and prolonging their storage time.Therefore,the total phenol content is used as the main indicator,and the nutrient index,in vitro antioxidant capacity and pH value of the dry fermented feed are measured at the same time.In order to compare two fermentation methods:anaerobic fermentation for a period of time followed by aerobic fermentation and aerobic fermentation for a period of time after anaerobic fermentation.The results show that no matter the total phenol content or reducing sugar content,the latter method is better than the previous one.So the subsequent orthogonal experiments will carry OTU deeper research and optimization on the latter fermentation method.Then,proceed with the optimization of the process from three fermentation conditions:fermentation mode,fermentation temperature,and bacterial content.The total phenol content of the dry fermented feed was used as the key evaluation index to select the best fermentation conditions.It can be seen from the orthogonal results that the fermentation method has the largest impact on the fermentation product,followed by the bacterial content,and the fermentation temperature has the smallest effect.According to the optimal solution with the highest total phenol content,the cotton is fastened after 24 hours,bacterial suspension is 7.9×10~6CFU/ml with 5%inoculation volume,material to water ratiot 2:1.Moreover,the total sugar content and DPPH free radical scavenging rate of this experimental group were the highest.Next,the crude protein content and amino acid content of the fermentation product under optimal conditions were determined.The test results showed that the crude protein content of the feed after fermentation was significantly increased(p<0.05).And the content of amino acids,not only essential but also non-essential were also increased significantly(p<0.05),the content of Glu was the highest.Finally,through microbial diversity analysis,it was found that Bacteroides are the dominant populations of feed materials,and the dominant population of fermented feeds is Lactobacillus,and the species abundance of fermented feeds is higher than that of raw materials.