添加乳酸菌和糖蜜对秸秆生物饲料的发酵品质及In vitro干物质消失率和瘤胃甲烷生成的影响

Effects of Adding Lactic Acid Bacteria and Molasses on Fermentation Characteristics and in Vitro Ruminal Methane Production of Corn Stover Silage

采用小规模发酵法,试验处理包括无添加组(对照组)、乳酸菌、糖蜜以及乳酸菌和糖蜜共同添加组。30 d后开封,乳酸菌和糖蜜添加组感官评分良好;乳酸菌、乳酸菌和糖蜜混合添加组的p H低于(P<0.05)对照组和糖蜜添加组。4个处理组的乳酸菌数量均在106~107(cfu·g^(-1))以上,3个添加组未检出酪酸菌和大肠杆菌,而酵母菌、耐热菌数量分别为102~106和103(cfu·g^(-1));对照组中大肠杆菌和酵母菌均为106(cfu·g^(-1))。糖蜜、乳酸菌以及二者共同添加组的In vitro干物质消失率显著高于对照组,而只有乳酸菌添加组的瘤胃甲烷生成量低于对照组。由此可见,添加乳酸菌、糖蜜以及二者混合添加均有助于秸秆发酵,抑制有害细菌的生长,能够得到高品质的玉米秸秆生物发酵饲料,并且添加乳酸菌可以降低秸秆生物饲料的In vitro瘤胃甲烷生成量。

A small-scale fermentation system was used and treatments were designed as control group without additive and experimental group with molasses（M）,lactic acid bacteria（LAB）,and M＋LAB. The silos were stored at room temperature for 30 days of fermentation,and sensory evaluation,p H and counts of viable microorganisms were determined. The silages treated by M,LAB and M＋LAB have high sensory score,and 106~107（cfu·g^（-1））LAB,no clostridia or coliform bacteria,and 103（cfu·g^（-1））bacilli and 102~106（cfu·g^（-1））yeasts. But the control silage had 107（cfu·g^（-1））LAB,106（cfu/g）coliform bacteria or yeasts. There was no difference for the moisture content among the four groups of silage. The values of pH for LAB and M＋LAB silage were significantly lower（P0.05）than that for the control silage or M silage. The results showed that adding LAB,M and M＋LAB inhibited the growth of the bad bacteria and improved the fermentation quality of the silage with dry corn stover,and got a good quality fermented feed,and the addition of LAB could decrease in vitro ruminal methane of the silage of dry corn stover.