Optimization of 0-8 Aspergillus oryzae Solid State Fermentation Conditions and the Effect of Fermented Product on Nutrient Digestion of Broiler

The high-yield protease was obtained by screening high-yield protease Aspergillus oryzae and optimizing its solid-state fermentation conditions, and then the effect of fermented product on nutrient digestion in broiler was studied. After the screening and re-screening of 8 different Aspergillus oryzae spores, a new Aspergillus oryzae strain 0-8 with high acid protease was obtained. The fermentation conditions of acid protease were optimized by single factor and orthogonal test experiment. The results showed that the optimum temperature was 30℃, the most suitable fermentation time was 66 h, the initial water content was 47.40%, the inoculation quantity was 1.5×10⁷ spores/mL, the content of bran was 80%, C/N was 1/3, the optimized vigor of acid protease reached 14 416.64 U/g, which was 157.02% higher than that before optimization. 500 mg/kg Aspergillus oryzae 0-8 fermented product was added in the broiler diet, and the mutrient digestibility of broiler were measured after 10 d of adaptation and 5 d of test period. The results of the nutrient digestion of broilers showed that feeding Aspergillus oryzae 0-8 fermentation increased the CP and energy digestibility of broiler in a certain degree compared to control group, but there's no significant difference (P>0.05). Dietary supplementation of Aspergillus oryzae fermentation was beneficial to the production of broilers, but its additive dose or feeding pattern should be further studied.