乳酸菌及酸处理对秸秆生物发酵饲料的化学成分及In vitro甲烷生成的影响

Lactic Acid Bacteria and Acid Treatment of Straw Fermentation Feed Effect of Chemical Composition and In vitro Methane Production

采用完全随机(添加处理5×发酵天数2)实验设计,对风干玉米秸秆进行无添加、乳酸菌(LAB)添加、酸液4%、6%和8%添加共计5个处理,发酵30 d和60 d开封。分析了p H、饲料化学成分、微生物组成及In vitro干物质消失率和甲烷生成量。经过发酵30及60 d的p H,LAB、4%、6%和8%的酸添加组均低于对照组,并且在相同添加组中,p H值随发酵时间的增加而显著下降。在饲料化学成分方面,所有添加组的有机物(OM)均高于对照组;LAB添加组的粗蛋白含量(CP)和粗脂肪(EE)均高于其他处理组。在微生物上,30或60 d的5个添加组的乳酸菌、耐热菌、一般细菌及酵母菌分别显著低于对照组;同时在每个处理中,各微生物60 d均低于30日。在In vitro干物质消失率和甲烷生成量方面,所有添加处理组的干物质消失率和甲烷生成量分别高于和低于对照组。以上结果表明,黄贮玉米秸秆的发酵品质60日好于30日,乳酸菌及混合酸处理玉米秸秆,均能提高黄贮玉米秸秆发酵品质,混合酸处理玉米秸秆能够不同程度降解秸秆中的粗纤维为非纤维性碳水化合物,乳酸菌和6%混合酸处理玉米秸秆可以提高In vitro干物质消失率,同时降低甲烷生成量。

A completely randomized design with a 5×2 [additive treatment （5）×fermentation day （2）] factorial treatment structure was used in this study, the experiment treatment included corn stover silage without or with lactic acid bacteria （LAB）,4%, 6% and 8% mixed acid,and the silage was opened on the 30 or 60 day of fermentation.The pH value,chemical composition,microbiological composition,in vitro rumen digestibility of dry matter （DDM） and methane production of corn stover silage were determined to study the effects of biological fermentation corn stover treated with LAB or acid on chemical composition and ruminal DDM and methane production in vitro.The pH value in LAB,4% ,6% and 8% groups were lower than that in the control,and with fermentation day extending,pH decreased.The OM or NDF in the all addition groups was higher or lower than that in the control,and the CP and EE in LAB group were the highest.The LAB, bacilli bacteria, aerobic bacteria and yeasts in the all addition groups were lower than those in the control on the 30th or 60th day of fermentation, and the microorganism＇s number on the 60th day was lower than that on the 30th day.In vitro DDM and methane production for all addition groups were higher,or lower than those for the control,respectively. The results suggested that he quality of the yellow corn silage on the 60th day was better than silage on the 30th day,adding both LAB and mixed acid could get good quality silage, and adding mixed acid could degrade NDF into non-fibrous carbohydrate,and either LAB or 6% mixed acid could increase in vitro DDM but decrease methane production of yellow corn stover silage.