不同饲料原料的体外发酵性能及产甲烷潜力

In vitro fermentation and methanogenic potential of different feed ingredients

优化日粮配方是减少反刍动物甲烷产生的最有效途径。本研究利用体外瘤胃液发酵技术,对14种饲料原料(糠麸、植物蛋白和谷物)体外发酵性能相关性及产甲烷潜力进行评估。根据各成分的产甲烷量将饲料配方分为高产、中产和低产类型,然后进行体外发酵,以确定实际产甲烷量及其对消化率的影响。结果:3类原料中总可消化养分水平最高的分别是棕榈粕、玉米DDGS和小麦。糠麸原料pH与除乙酸与丙酸比值外的所有参数均呈负相关,而乙酸与丙酸比值与除pH、CO2外的所有参数均呈负相关,植物蛋白原料pH和乙酸与丙酸比值呈正相关,而这两个参数与其他参数呈负相关,而谷物原料为基质进行体外发酵时,pH与乙酸与丙酸比值为正相关,而与其他参数表现为负相关。当以玉米皮、棉粕和大麦作为基质孵育72 h后,甲烷产量最低,而以本地麸皮、豆粕和玉米为基质时,甲烷产量最高。结论:低产甲烷饲料配方可以降低甲烷产量,但提高了非纤维碳水化物、总可消化养分和挥发性脂肪酸产量。

Optimizing dietary formulations is the most effective way to reduce methane.Using in vitro rumen fermentation technology,this study evaluated the correlation of in vitro fermentation performance and methane-producing potential of 14 feed materials(bran,plant protein and grain).According to the amount of methane produced by each component,the feed formula was divided into high yield,middle yield and low yield types,and then in vitro fermentation was conducted to determine the actual amount of methane produced and its effect on digestibility.Results:the highest levels of total digestible nutrients were found in palm meal,corn DDGS and wheat.Bran raw materials pH and besides acetic acid/propionic acid ratio of all parameters are negatively correlated,and acetic acid/propionic acid ratio with the exception of the pH,CO2 all parameters are negatively correlated,plant protein raw materials pH and acetic acid/propionate ratio were positively correlated,and the two parameters and other parameters are negatively correlated,while in vitro fermentation,corn raw materials for the substrate,the pH was positively associated with acetic acid/propionic acid ratio,and show the negative correlation with other parameters.Methane production was lowest when corn husk,cotton meal and barley were incubated for 72 h,and highest when local bran,soybean meal and corn were used as substrate.Conclusion:low methane feed formula can reduce methane production but increase non~fiber carbohydrate,total digestible nutrient and volatile fatty acid production.