西藏地区不同作物秸秆体外发酵特性研究

本试验旨在利用体外产气法评定西藏地区不同作物秸秆的营养价值。选取西藏地区5种常见作物秸秆(豌豆秸秆、玉米秸秆、青稞秸秆、小麦秸秆、油菜秸秆),通过单因素试验设计,利用体外产气法评定5种作物秸秆体外发酵48 h的产气量、理论最大产气量(Vf)、甲烷(CH4)产量、逻辑斯谛-指数(LE)模型产气参数、发酵液p H和氨态氮(NH3-N)浓度、主要挥发性脂肪酸(VFA)产量、体外干物质降解率(IVDMD)和体外中性洗涤纤维降解率(IVNDFD)等指标。结果显示:5种作物秸秆体外发酵48 h的产气量按玉米秸秆、青稞秸秆、豌豆秸秆、小麦秸秆、油菜秸秆的顺序依次降低。体外发酵48 h后,玉米秸秆的Vf、IVDMD、IVNDFD、CH4产量(豌豆秸秆除外)、丙酸和总VFA产量均显著高于其他4种作物秸秆(P0.05),其体外发酵液p H则显著低于其他秸秆(P0.05)。结果表明,玉米秸秆体外发酵效果最佳,与其他试验作物秸秆相比更容易被瘤胃微生物降解利用。

Study on in Vitro Fermentation Characteristics of Different Crop Straws in Tibet Region

This experiment aimed to evaluate the nutritional value of different crop straws in Tibet region using in vitro gas production technology.Five kinds of common crop straws (common vetch straw, maize straw,hullessbarley straw, wheat straw and rape straw) were selected in Tibet region, and the 48 h gas production,theoretical maximum gas production (Vf), methane (CH4) production, gas production parameters of logisticexponential (LE) model, pH and ammonia nitrogen (NH3-N) concentration in fermented fluid, main volatile fatty acids (VFA) production, in vitro dry matter degradability (IVDMD) and in vitro neutral detergent fiber degradability (IVNDFD) of five kinds of crop straws were determined using in vitro gas production technique by the single factor experimental design.The results showed that the 48 h gas production of five kinds of crop straws reduced in the order of maize straw, hullessbarley straw, common vetch straw, wheat straw and rape straw.After 48 h in vitro fermentation, the Vf, IVDMD, IVNDFD, CH4 production, propionic acid and total VFA yields of maize straw were significantly higher than those of the other four kinds of crops straws (P<0.05), while the in vitro fermented fluid pH of maize straw was significantly lower than that of the other four kinds of crop straws (P<0.05).The results indicate that the maize straw possesses the best in vitro fermentation effect and it is more easily to be utilized by the rumen microorganisms compare with the other crop straws in this experiment.Chinese Journal of Animal Nutrition, 2017, 29 (2) :719-728]