Dong Zhihao, Wang Siran, Zhao Jie, Li Junfeng, Liu Qinhua, Bao Yuhong, Shao Tao
Institute of Ensiling and Processing of Grass, College of Agro-grassland Science, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China.
Institute of Grassland Science, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa 850000, China.
Anim Biosci. 2021 Feb;34(2):223-232. doi: 10.5713/ajas.19.0972. Epub 2020 Apr 12.
To investigate the improvement in utilization efficiency of total mixed ration (TMR) on Tibetan plateau, TMR were ensiled with different additives.
A total of 150 experimental silos were prepared in a completely randomized design to evaluate the six treatments: i) control (without additive), ii) Lactobacillus buchneri (L. buchneri), iii) acetic acid, iv) propionic acid, v) 1,2-propanediol; and vi) 1-propanol. After 90 days of ensiling, silos were opened for fermentation quality and in vitro analysis, and then subjected to an aerobic stability test for 14 days.
Treating with L. buchneri, acetic acid, 1,2-propanediol and 1-propanol decreased propionic acid contents and yeast number, whereas increased (p<0.05) pH, acetic acid and ethanol contents in the fermented TMR. Despite increased dry matter (DM) loss in the TMRs treated with 1,2-propanediol and 1-pronanol, additives did not affect (p>0.05) all in vitro parameters including gas production at 24 h (GP24), GP rate constant, potential GP, in vitro DM digestibility and in vitro neutral detergent fibre digestibility. All additives improved the aerobic stability of ensiled TMR to different extents. Specially, aerobic stability of the ensiled TMR were substantially improved by L. buchneri, acetic acid, 1,2-propanediol, and 1-propanol, indicated by stable pH and lactic acid content during the aerobic stability test.
L. buchneri, acetic acid, 1,2-propanediol, and 1-propanol had no adverse effect on in vitro digestibility, while ensiling TMR with the additives produced more acetic acid and ethanol, subsequently resulting in improvement of aerobic stability. There is a potential for some fermentation boosting additives to enhance aerobic stability of fermented TMR on Tibetan plateau.
为研究不同添加剂对全混合日粮（TMR）在青藏高原利用率的改善效果，对TMR进行青贮处理。
采用完全随机设计，共制备150个试验青贮窖，评估6种处理：i）对照（无添加剂），ii）布氏乳杆菌（L.布氏乳杆菌），iii）乙酸，iv）丙酸，v）1,2 -丙二醇；和vi）1 -丙醇。青贮90天后，打开青贮窖进行发酵品质和体外分析，然后进行14天的好氧稳定性测试。
用布氏乳杆菌、乙酸、1,2 -丙二醇和1 -丙醇处理可降低丙酸含量和酵母数量，同时提高（p<0.05）发酵TMR的pH值、乙酸和乙醇含量。尽管用1,2 -丙二醇和1 -丙醇处理的TMR干物质（DM）损失增加，但添加剂对所有体外参数均无影响（p>0.05），包括24小时产气量（GP24）、产气速率常数、潜在产气量、体外干物质消化率和体外中性洗涤纤维消化率。所有添加剂均不同程度地提高了青贮TMR的好氧稳定性。特别是，布氏乳杆菌、乙酸、1,2 -丙二醇和1 -丙醇显著提高了青贮TMR的好氧稳定性，好氧稳定性测试期间pH值和乳酸含量稳定表明了这一点。
布氏乳杆菌、乙酸、1,2 -丙二醇和1 -丙醇对体外消化率无不良影响，而用这些添加剂青贮TMR可产生更多乙酸和乙醇，从而提高好氧稳定性。一些发酵促进添加剂有可能提高青藏高原发酵TMR的好氧稳定性。
