Chemical composition and in vitro digestibility of corn stover during field exposure and the fermentation characteristics of silage prepared with microbial additives
Chemical composition and in vitro digestibility of corn stover during field exposure and the fermentation characteristics of silage prepared with microbial additives
复制标题
玉米秸秆田间暴露化学成分、体外消化率及微生物添加剂制备青贮饲料的发酵特性
DOI：
10.5713/ajas.18.0886
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发表时间：
2019-12-01
期刊：
影响因子：
--
通讯作者：
Cai, Yimin
中科院分区：
文献类型：
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作者：
Gao, Jun Lei;Wang, Peng;Cai, Yimin
目的为有效利用玉米秸秆资源作为动物饲料，研究玉米秸秆的化学成分、体外消化率以及乳酸菌和纤维素酶制备青贮饲料的发酵特性。方法在成熟期收获玉米穗，包括玉米穗轴和玉米壳。将玉米秸秆暴露在自然天气条件下的田地中。在暴露0、2、4、7、15、30和60 d后制备青贮饲料。将玉米秸秆切成约1至2cm长，然后装入5升塑料筒仓中。青贮密度为550.1±20.0 g/L新鲜物质，并且筒仓保持在室温（10°C至25°C）下。青贮饲料处理设计如下：无添加剂（对照）、有LAB、有纤维素酶和有LAB+纤维素酶。发酵45 d后，打开筒仓进行化学成分、发酵质量和体外消化分析。结果玉米秸秆收获后，水分含量为78.19%，粗蛋白含量为9.01%，中性洗涤纤维含量为64.54%。玉米秸秆的DM、NDF和酸性洗涤纤维（ADF）含量增加，而CP和水溶性碳水化合物含量以及DM和CP的体外消化率降低（p<0.05）。与对照相比，纤维素酶处理的青贮饲料NDF和ADF含量显著降低（p<0.05）。乳酸菌、纤维素酶、乳酸菌+纤维素酶处理的青贮料pH值均低于对照组，乳酸含量高于对照组（p<0.05）。与对照组或LAB处理的青贮饲料相比，纤维素酶或LAB+纤维素酶处理的青贮饲料提高了体外干物质消化率（IVDMD）（p<0.05）。结论玉米秸秆在田间暴露过程中会造成营养物质的损失，应采用新鲜原料制备玉米秸秆青贮饲料，乳酸菌和纤维素酶可提高青贮饲料的发酵和IVDMD。
Objective To effectively use corn stover resources as animal feed, we explored the chemical composition and in vitro digestibility of corn stover during field exposure and the fermentation characteristics of silage prepared with lactic acid bacteria (LAB) and cellulase. Methods Corn ears including the cobs and shucks were harvested at the ripe stage. The corn stover was exposed in the field under natural weather conditions. Silages were prepared after 0, 2, 4, 7, 15, 30, and 60 d of exposure. Corn stover was chopped into approximately 1 to 2 cm lengths and then packed into 5 liter plastic silos. The ensiling density was 550.1±20.0 g/L of fresh matter, and the silos were kept at room temperature (10°C to 25°C). Silage treatments were designed as follows: without additives (control), with LAB, with cellulase, and with LAB+ cellulase. After 45 d of fermentation, the silos were opened for chemical composition, fermentation quality and in vitro digestion analyses. Results After harvest, corn stover contained 78.19% moisture, 9.01% crude protein (CP) and 64.54% neutral detergent fiber (NDF) on a dry matter (DM) basis. During field exposure, the DM, NDF, and acid detergent fiber (ADF) contents of corn stover increased, whereas the CP and water-soluble carbohydrate contents and in vitro digestibility of the DM and CP decreased (p<0.05). Compared to the control silage, cellulase-treated silage had lower (p<0.05) NDF and ADF contents. The pH values were lower in silage treated with LAB, cellulase, or LAB+cellulase, and lactic acid contents were higher (p<0.05) than those of the control. Silage treated with cellulase or LAB+cellulase improved (p<0.05) the in vitro DM digestibility (IVDMD) compared to that of the control or LAB-treated silage. Conclusion Corn stover silage should be prepared using fresh materials since stover nutrients are lost during field exposure, and LAB and cellulase can improve silage fermentation and IVDMD.