Study On Fermented Feed By Solid State Fermentation Of Wheat Bran

With the development of animal husbandry, the shortage of feed resources has attracted much attention. Wheat bran is one of China’s staple agricultural resources, but it contains large amounts of crude fiber with poor quality. Crude protein is low and amino acid content can not meet the nutritional demand of pigs and chickens. In this paper, solid state fermentation technology was used to increase nutrition composition and degrade anti-nutrition factors in wheat bran. We hope that we can improve nutrients of wheat brand and reduce feed costs at the same time.A yeast strain with high production of protein was screened from distiller feed, named yeast Ⅱ. And then, yeast Ⅱ was used for protein feed production with solid-state fermentation in wheat bran medium.. Fermentation conditions were optimized with single factor and orthogonal test design. Results showed that the optimum fermentation conditions were: incubated at30℃, inoculum at10%, the medium with addition of4%glucose, fermentation for48h in wheat bran medium with liquid-solid ratio at1:1. The content of crude protein in fermentation products reached23.5%, which increased by24.6%to that of the unfermented.Aspergillus niger I with high cellulase activity was screened from the laboratory preserved strains by the selective medium-cellulose Congo red medium, and the bran medium for re-screening. And then, yeast Ⅱ and the stain of Aspergillus niger I with high cellulase activity were used for protein feed production with multi-strains through solid-state fermentation. Fermentation conditions were optimized with single factor and orthogonal test design. Results showed that the optimum fermentation conditions were:incubated at30℃, inoculum at10%, ratios of inoculation2:1for yeast Ⅱ:Aspergillus niger I, and the medium with addition of2%glucose, fermentation for48h in wheat bran medium with liquid-solid ratio at1:1. The content of crude protein in fermentation products reached25.26%, which increased by33.93%to that of the unfermented. Results showed that feed by mixed strains fermentation was obvious better than that by single strain fermentation.Levels of main nutrition and crude fiber in wheat bran were determined after fermentation. Nutrition levels increased significantly in wheat bran with no bad smell. Crude protein content and crude fiber content in fermented feed has reached the standard of protein feed. The fermented feed is a novel protein feed with certain value. In a word, the wheat bran has been a high-quality protein feed after fermentation.