Pan Liyi, Harper Karen, Queiroz Oscar, Copani Giuseppe, Cappellozza Bruno I
University of Queensland, School of Agriculture and Food Sciences, Gatton 4343, Australia.
Chr. Hansen A/S, Hørsholm 2970, Denmark.
Transl Anim Sci. 2022 May 17;6(2):txac067. doi: 10.1093/tas/txac067. eCollection 2022 Apr.
Two experiments evaluated the effects of a -based direct-fed microbial () on in vitro dry matter () and neutral detergent fiber (; experiment 1) and starch (experiment 2) digestibility of a variety of ruminant feedstuffs. In experiment 1, 10 forage sources were evaluated: ryegrass, alfalfa hay, leucaena, corn silage, spinifex, buffel grass, flinders grass, Mitchell grass, Rhodes grass hay, and Queensland bluegrass. Experimental treatments were control (forages with no probiotic inoculation; ) and forage sources inoculated with a mixture containing and (3.2 × 10 CFU per g; DFM). In vitro DM and NDF digestibility were evaluated at 24- and 48-h post-treatment inoculation. Treatment × hour interactions were noted for IVDMD (in vitro dry matter digestibility) and IVNDFD (in vitro neutral detergent fibre digestibility) ( ≤ 0.05). More specifically, DFM inoculation increased ( ≤ 0.03) IVDMD at 24 h in four forages and increased 48-h IVDMD ( ≤ 0.02) in alfalfa hay, ryegrass, leucaena, and Mitchell grass hay, but opposite results were observed for Queensland bluegrass ( < 0.01). A 24- and 48-h IVNDFD increased following DFM inoculation ( ≤ 0.02) in five forage sources, but reduced for Queensland bluegrass ( < 0.01). When the forages were classified according to their quality, main treatment effects were detected for IVDMD ( ≤ 0.02) and IVNDFD ( < 0.01). In experiment 2, five common cereal grains were evaluated-high-density barley (82 g/100 mL), low-density barley (69 g/100 mL), corn, sorghum, and wheat-under the same treatments as in experiment 1. In vitro starch digestibility () was evaluated at 6- and 12-h following treatment inoculation. Treatment × hour interactions were observed for starch digestibility in three out of five concentrate sources ( ≤ 0.001). Inoculation of DFM yielded greater 24-h starch digestibility for high-, low-density barley, and wheat ( ≤ 0.02), but also greater at 48 h in wheat ( < 0.0001). Moreover, mean starch digestibility improved for corn and sorghum inoculated with DFM ( < 0.01). Using a -based DFM ( and ) improved the mean in vitro DM and NDF digestibility of different forage sources of varying qualities (based on crude protein content). Similarly, IVSD was also greater following DFM inoculation, highlighting the potential of this probiotic to improve nutrient digestibility and utilization in the beef and dairy cattle herd.
两项试验评估了基于α的直接投喂微生物（DFM）对多种反刍动物饲料原料体外干物质（DM）和中性洗涤纤维（NDF；试验1）以及淀粉（试验2）消化率的影响。在试验1中，评估了10种草料来源：黑麦草、苜蓿干草、银合欢、玉米青贮、滨刺草、水牛草、弗林德斯草、米切尔草、罗德干草和昆士兰蓝草。试验处理为对照（未接种益生菌的草料；CON）和接种含有嗜酸乳杆菌和双歧杆菌混合物（每克3.2×10⁹CFU；DFM）的草料来源。在处理接种后24小时和48小时评估体外DM和NDF消化率。观察到处理×时间对体外干物质消化率（IVDMD）和体外中性洗涤纤维消化率（IVNDFD）有交互作用（P≤0.05）。更具体地说，DFM接种使4种草料在24小时时IVDMD增加（P≤0.03），并使苜蓿干草、黑麦草、银合欢和米切尔干草在48小时时IVDMD增加（P≤0.02），但昆士兰蓝草的结果相反（P<0.01）。在5种草料来源中，DFM接种后24小时和48小时的IVNDFD增加（P≤0.02），但昆士兰蓝草的IVNDFD降低（P<0.01）。当根据草料质量进行分类时，检测到IVDMD（P≤0.02）和IVNDFD（P<0.01）的主要处理效应。在试验2中，评估了5种常见谷物——高密度大麦（82克/100毫升）、低密度大麦（69克/100毫升）、玉米、高粱和小麦——采用与试验1相同的处理。在处理接种后6小时和12小时评估体外淀粉消化率（IVSD）。在5种精料来源中的3种观察到处理×时间对淀粉消化率有交互作用（P≤0.001）。DFM接种使高密度、低密度大麦和小麦在24小时时淀粉消化率更高（P≤0.02），在小麦48小时时也更高（P<0.0001）。此外，接种DFM的玉米和高粱的平均淀粉消化率提高（P<0.01）。使用基于α的DFM（嗜酸乳杆菌和双歧杆菌）提高了不同质量（基于粗蛋白含量）草料来源的平均体外DM和NDF消化率。同样，DFM接种后IVSD也更高，突出了这种益生菌提高肉牛和奶牛群营养消化率和利用率的潜力。
