| Straw has poor palatability and quality,low nutrient conversion rate,and poor direct feeding effect as ruminant feed.Fermentation of straw storage is an important way to improve the utilization of straw as feed,and among the factors affecting its quality,the type of fermentation preparation and its ratio are particularly important.This topic uses three typical straw resources of reed,corn and rice straw as raw materials to study the fermentation effect of different enzyme preparations,improve the utilization rate of reed,corn and rice straw,and provide a theoretical basis for the feed utilization of the three.According to the relevant literature,the combination of different types of enzymes and bacterial agents and the amount of addition are determined.The specific test treatment is as follows:(1)In the storage fermentation test of reed straw,there were 6 treatments with 3 replicates for each treatment,and they were: Control group(LCK group),basic group(LWA group,0.08 g Aspergillus Niger+0.016 g Bacillus subtilis +0.125 g Candida prion producing +1 g glucanase),Aspergillus Niger group(LWB group,0.16 g Aspergillus Niger +0.016 g Bacillus subtilis +0.125 g Candida prion +1 g glucanase),Bacillus subtilis group(LWC group,0.08 g Aspergillus Niger +0.032 g Bacillus subtilis +0.125 g candida prion +1 g glucanase),Candida prion group(LWD group,0.08 g Aspergillus Niger +0.016 g Bacillus subtilis +0.250 g candida prion +1 g glucanase)and glucanase group(LWE group,0.08 g Aspergillus Niger +0.016 g Bacillus subtilis +0.125 g candida prion +2 g glucanase).Only 500 m L of distilled water was added to the LCK group.(2)In the corn straw fermentation test,6 groups were set up,each treatment had 3 replicates,and each treatment was: Control group(YCK group),basic group(YMA group,0.04 g Aspergillus Niger +0.008 g Bacillus subtilis +0.0625 g candida prion +1g glucanase),Aspergillus Niger(YMB group,0.12 g Aspergillus Niger +0.008 g Bacillus subtilis +0.0625 g candida prion +1g glucanase),Bacillus subtilis(YMC group,0.04 g Aspergillus Niger +0.024 g Bacillus subtilis +0.0625 g candida prion +1 g glucanase),Candida prion(YMD group,0.04 g Aspergillus Niger +0.008 g Bacillus subtilis +0.1875 g Candida prion +1 g glucanase)and glucanase(YME group,0.04 g Aspergillus Niger +0.008 g Bacillus subtilis +0.0625 g candida prion +2 g glucanase).Only 710 m L of distilled water was added to the YCK group.(3)In the rice straw stalk fermentation test,6 groups were set up,each treatment had 3 replicates,and each treatment was: Control group(DCK group),basic group(DCA group,0.06 g Aspergillus Niger +0.012 g Bacillus subtilis +0.125 g candida prion producing +1 g glucanase),Aspergillus Niger group(DCB group,0.12 g Aspergillus Niger +0.012 g Bacillus subtilis +0.125 g candida prion +1 g glucanase),Bacillus subtilis group(DCC group,0.06 g Aspergillus Niger +0.024 g Bacillus subtilis +0.125 g candida prion +1 g glucanase),Candida prion group(DCD group,0.06 g Aspergillus Niger +0.012 g Bacillus subtilis +0.250 g candida prion +1 g glucanase group)and glucanase group(DCE group,0.06 g Aspergillus Niger +0.012 g Bacillus subtilis +0.125 g candida prion +2 g glucanase group).Only 570 m L of distilled water was added to the DCK group.In addition,20 ml molasses,0.0665 g of Lactobacillus plantarum,0.02 g of Pediococcus pentose,0.12 g of Lactobacillus bushy,0.5 g of lusanase and 500 ml of pure water were added to the experimental groups,fermentation substrates are 500 g and the moisture content of straw in each group was controlled at 65%Three kinds of straw were stored and fermented for 90 days,and the sensory evaluation was carried out to measure fermentation quality indexes,nutritional quality indexes and high-throughput sequencing.The main test findings were the following:(1)In terms of sensory evaluation,the reed,corn and rice straw straws improved in odor score,structure score and total score after yellow silage compared with the control group(P<0.05),and were all graded as first class excellent,while the control group was graded as third class medium..In terms of fermentation quality,compared with the control group,The p H of each test group was found to be significantly lower than that of the the controlling group(P<0.05),and all were less than 3.69.The lactic acid(LA)content was significantly higher(P<0.05)and the propionic acid(PA),butyric acid(BA)and ammoniacal nitrogen to total nitrogen(NH4-N/TN)ratios were significantly lower(P<0.05)in each test group as compared to the controls In the corn straw storage fermentation experiment,compared with the control group,the p H value of experimental groups was significantly lower than that of the control group(P<0.05),and all were lower than 3.70.Compared with the control group,LA content in experimental groups was significantly higher than that in the control group(P<0.05),ammonia nitrogen(NH4-N)content and NH4-N/TN ratio in experimental groups were significantly lower than that in the control group(P<0.05),and no BA and PA were detected after corn straw storage.In the fermentation experiment of straw storage,The p H,NH4-N content and NH4-N/TN ratio were found to be significantly lower in each test group compared to the control group(P<0.05),where the p H value was lower than 3.82.The LA content was significantly higher in each test group compared to that in the control group(P<0.05),and the LA/TA ratio was significantly higher in the DCA,DCD and DCE groups compared to that in the control group(P <0.05).BA and PA were not detected in rice straw straw after yellow silage.(2)In terms of nutritional quality,compared with the control group of fermentation tests,the contents of CP,EE and GE in experimental groups were significantly increased after storage and fermentation of reed,corn and straw(P<0.05),The Ash,NDF and ADF contents were lowered remarkably(P<0.05).LWD group,YMC group and DCD group increased CP content the most in each fermentation test,while the NDF and ADF degradation rates were highest in LWC group,YMC group and DCC group.Overall,LWC,YMC and DCC groups had the highest nutritional quality after fermentation.(3)According to the membership function analysis and comprehensive evaluation based on the fermentation quality index and nutritional quality index,it was found that the fermentation quality and nutritional quality of reed,corn and straw straw after storage could be improved by the combination of different enzyme and bacteria preparations.Among them,LWC,YMC and DCC groups had the highest comprehensive scores in the fermentation quality and nutritional quality.(4)Through high-throughput sequencing,species richness and diversity of reed,corn and straw were reduced by different enzyme bacteria preparations.The dominant bacteria after fermentation were Firmicutes and Proteobacteria,and Lactobacillus.Through the correlation analysis between the microorganisms and fermentation quality and nutritional quality of reed straw stored,Hexanoic acid producing bacteria spp.were found to be significantly and positively correlated with AA,BA and PA contents(P<0.05).There was a significant positive correlation between Lactobacillus and EE content(P<0.05).Through the analysis of the correlation between the microorganisms and the fermentation quality and nutritional quality of corn straw after storage,it was found that lactic acid bacteria had a significant positive correlation with LA content(P<0.05),and a significant negative correlation with ADF(P<0.05).Raenella was positively correlated with NDF(P<0.05).According to the correlation analysis between the microorganisms and the fermentation quality and nutritional quality after straw storage,it was found that lactic acid bacteria had a significant positive correlation with cp content(P<0.05),and a significant negative correlation with p H value,AA,BA and Ash content(P<0.05).In summary,the combination of different enzyme and bacteria preparations to treat reed,corn and rice straw for yellow storage can improve their fermentation quality and nutritional quality,and reduce the diversity and richness of species.Through the comprehensive analysis of the membership function,it was found that the LWC group(Bacillus subtilis group),YMC group(Bacillus subtilis group)and DCC group(Bacillus subtilis group)had the best fermentation effects,and the comprehensive evaluation concluded that the addition ratio of these three groups of enzyme preparations was the most suitable for the three kinds of straw. |
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