Effects of Aspergillus oryzae Inclusion on Corn Silage Fermentation

This study is aimed at evaluating the effect of Aspergillus oryzae fermentation extract (AFE) on corn silage fermentation characteristics. Trial included two groups of treatments, with or without AFE inclusion in corn ensilage. Sixty corn silage containers, including two treatments with thirty replicates each, were processed in a laboratory scale mini-silo of 21 cm radius by 45 cm height. Three replicate containers were opened and sampled for analysis at 0, 0.5, 1, 2, 3, 4, 6, 10, 18 and 34 days after being ensiled. One silage container from each treatment was installed with a remote controlled electronic thermometer to record the temperature changes. Analysis included silage temperature, pH, fermentation acids, the water-soluble carbohydrates and chemical compositions and the silage protein fractions. Results showed that on the first day, the temperature of the ensiled corn was slightly higher than room temperature, but returned to room temperature on the second day. The pH and concentrations of WSC, ADF, lignin and acetic acid in the AFE treated silage were significantly lower than the control groups (p<0.05). The lactic acid and crude protein on the other hand were significantly higher in the AFE treated silage as compared to the control (p<0.05) at the end of the ensilage period. The DM content was significantly higher (p<0.05) whereas the butyric acid content of the AFE treated silage was significantly lower (p<0.05) than the control at the end of the 34 day ensilage period. Titratable acid and buffering capacity in the corn silage were not significantly different between treatment groups (p>0.05). Ammonia N concentration in the AFE treated silage showed a trend of decrease (p>0.05). NPN and the protein fraction A in both groups increased during the conservation period, but fraction A in the AFE treated corn silage was significantly higher than the control silage (p<0.05). During the conservation period, the AFE treated corn silage showed a trend toward a decrease in fractions $B_1$, $B_3$ and C (p<0.05). The protein fraction B2 showed a trend toward increase in the control group and an inconsistent trend in the AFE treated silage during the ensiling period. The AFE treated silage showed a better Flieg score over the control silage (97 vs. 75) as calculated from the concentrations of lactic acid, acetic acid and butyric acid.