Gao Jun Lei, Wang Peng, Zhou Chang Hai, Li Ping, Tang Hong Yu, Zhang Jia Bao, Cai Yimin
College of Animal Science, Jilin University, Changchun 130062, China.
School of Architecture and Civil Engineering, Changchun Sci-Tech University, Changchun 130600, China.
Asian-Australas J Anim Sci. 2019 Dec 1;32(12):1854-1863. doi: 10.5713/ajas.18.0886. Epub 2019 Apr 15.
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.
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 1-2 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 (10-25°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.
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.
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.
为有效利用玉米秸秆资源作为动物饲料，我们探究了田间暴露期间玉米秸秆的化学成分和体外消化率，以及用乳酸菌（LAB）和纤维素酶制备的青贮饲料的发酵特性。
在成熟阶段收获包括玉米穗轴和苞叶的玉米穗。将玉米秸秆在自然天气条件下暴露于田间。在暴露0、2、4、7、15、30和60天后制备青贮饲料。将玉米秸秆切碎至约1 - 2厘米长，然后装入5升塑料青贮容器中。青贮密度为每升新鲜物质550.1±20.0克，青贮容器保持在室温（10 - 25°C）。青贮处理设计如下：无添加剂（对照）、添加LAB、添加纤维素酶、添加LAB + 纤维素酶。发酵45天后，打开青贮容器进行化学成分、发酵质量和体外消化分析。
收获后，以干物质（DM）计，玉米秸秆含有78.19%的水分、9.01%的粗蛋白（CP）和64.54%的中性洗涤纤维（NDF）。在田间暴露期间，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）。与对照青贮饲料相比，纤维素酶处理的青贮饲料NDF和ADF含量较低（p<0.05）。用LAB、纤维素酶或LAB + 纤维素酶处理的青贮饲料pH值较低，乳酸含量高于对照（p<0.05）。与对照或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（p<0.05）体外干物质消化率（IVDMD）。
由于田间暴露期间秸秆养分流失，应使用新鲜材料制备玉米秸秆青贮饲料，并且LAB和纤维素酶可改善青贮饲料发酵和IVDMD。
