| Solid state fermentation was applied in this study. By the measurement of the pH, DMR, and reducing sugar of the fermented feed, studied the variation disciplinarians of the fermentation parameters, what were affected by the probiotics and B vitamins. Selected the appropriate proportion of the different probiotics and established the pattern of optimum combination of the B vitamins.The appropriate proportion of the lactic acid bacteria, Bacillus subtilis, Yeast was determined through the L9 (33) orthogonal test. The experiment was divided into 9 models according to 3 levels of three probiotics (lactic acid bacteria, Bacillus subtilis, Yeast). And solid state fermentation was implemented at 30?35?. The result indicated that pH decreased significantly (P< 0.05) along with the fermentation time, and it showed a quadratic curve variation (P< 0.01). Analyzed with the mathematical models, the first-order or second-order coefficients of fitting equation were significant different (P< 0.01), and there were no differences among the constant term (P> 0.05). Three probiotics supplemented according to 2:2:2 or 2:2:3, pH decreased rapidly (P< 0.05). The reducing sugar increased significantly along with the fermentation time, and it was even more obvious with adding 2:2:2,2:2:3 or 3:3:3 of the probiotics (P< 0.05). Dry matter (DM) of the whole fermentation process had a certain loss; and DMR decreased significantly along with the fermentation time, but there were no differences among the treatments. In summary, under the condition of this experiment, the appropriate proportion of lactic acid bacteria, Bacillus subtilis, Yeast was 2:2:2.Single-factor experimental design was employed to study the variation disciplinarians of the pH, DMR, and reducing sugar of the fermented feed, what were formulated as different proportion (24:0,12:11,0:23) of soybean meal and cottonseed meal. The analysis showed that pH decreased significantly (P< 0.05) along with the fermentation time, and it showed a quadratic curve variation (P< 0.01). There were no differences among the first-order, second-order coefficients or constant term of fitting equation (P> 0.05), respectively. The reducing sugar increased significantly along with the fermentation time (P< 0.05), however, there were no differences among the treatments. Losses of the DM were increased significantly along with the fermentation time (P< 0.05); and DMR decreased significantly (P< 0.05) along with the fermentation time, however, there were no differences among the treatments. In summary, under the condition of this experiment, the fermented feed what were formulated as different proportion (24:0,12:11,0:23) of soybean meal and cottonseed meal, had no differences between each other. Also, the process of fermentation was basically the same.Central composite design of response surface methodology (RSM) was employed to optimize vitamin B1 content (X1:0.6?1.0 mg/kg), vitamin B2 content (X2:0.6?1.8 mg/kg) and vitamin B12 content (X3:9?15?g/kg). After 72 h solid-state fermented, samples from three fermented feed/pen and 3 replicate pens/treatment were obtained to evaluate the pH value, dry matter recovery and reducing-sugar content. Results indicated that the data of pH value, DMR and reducing-sugar were adequately fitted into three second-order polynomial models (P< 0.05). The vitamin B1, B2 and B12 were found to have significant linear, quadratic and interaction effects on the pH value, DMR and reducing-sugar (P< 0.05). The optimal extraction conditions were predicted to be vitamin B1 content of 0.65 mg/kg, vitamin B2 content of 1.29 mg/kg and vitamin B12 content of 12.02?g/kg. The pH value, DMR and reducing sugar were predicted by RSA to be 4.09,91.57% and 6.46%, respectively. These detection indexes what obtained through the verification experiment were close to the predicted values significantly (P< 0.01). The establishment of such a model provides a good experimental basis with employing RSM for optimizing the inoculation amount of vitamin B1 (0.65 mg/kg), vitamin B2 (1.29 mg/kg) and vitamin B12 (12.02 ?g/kg) to improve the quality of fermented feed. The model was employed to the verification experiment, it found that pH was decreased by 4.29%, and the reducing-sugar was increased by 2.23%(P< 0.01)In summary, the appropriate proportion of probiotics was selected to be lactic acid bacteria, Bacillus subtilis, Yeast= 2:2:2. The fermentation parameters had no differences among the different proportion of soybean meal and cottonseed meal. The pattern of optimum combination of vitamin B1, B2 and B12 was established as 0.65 mg/kg,1.29 mg/kg and12.02 ?g/kg, respectively. |
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