Weiss K, Kroschewski B, Auerbach H
Humboldt Universität zu Berlin, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, D-10115 Berlin, Germany.
Humboldt Universität zu Berlin, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, D-10115 Berlin, Germany.
J Dairy Sci. 2016 Oct;99(10):8053-8069. doi: 10.3168/jds.2015-10323. Epub 2016 Aug 4.
Ensiling conditions strongly influence fermentation characteristics, yeast count, and aerobic stability. Numerous volatile organic compounds including esters are produced, which may negatively affect feed intake and animal performance and air quality. In addition to a farm survey, 3 laboratory experiments were carried out to study the effects of air (by delayed sealing or by air infiltration during anaerobic storage), temperature (20 and 35°C), and various types of additives [blends of either sodium benzoate and sodium propionate (SBSP) or of sodium benzoate and potassium sorbate (SBPS); buffered mixture of formic and propionic acids (FAPA); homofermentative inoculant (LAB)]. After additive treatment, chopped whole corn plants were packed into 1.5-L glass jars and stored for several months. For treatments with air infiltration, glass jars with holes in the lid and body were used. The farm survey in 2009 revealed large variation in lactate, acetate, ethanol, n-propanol, and 1,2-propanediol concentrations. Whereas ethyl esters were detected in all silages, the mean ethyl lactate concentrations were higher than those for ethyl acetate (474 vs. 38mg/kg of dry matter). In the ensiling experiments, few unequivocal effects of the tested factors on the analyzed parameters were observed due to many interactions. Delayed ensiling without additives decreased lactic acid production but, in one trial, increased acetic acid and had no effect on ethanol. The effect of delayed sealing on yeast counts and aerobic stability differed widely among experiments. Air infiltration during fermentation tested in one trial did not alter lactic acid production, but resulted in more acetic acid in delayed and more ethanol than in promptly sealed untreated silages. Greater ethanol production was associated with increased yeast numbers. Storage at high temperature resulted in lower lactic acid and n-propanol, and a trend toward reduced ethanol production was observed. The additive FAPA consistently caused increased ethanol and reduced n-propanol levels with no effect on yeast counts and aerobic stability. When the additives SBSP and SBPS decreased n-propanol and ethanol, reduced yeast counts were also found. Ethyl ester formation was strongly correlated with those of ethanol and to a lesser degree with those of the respective acid.
青贮条件对发酵特性、酵母数量及有氧稳定性有强烈影响。会产生包括酯类在内的众多挥发性有机化合物，这可能对采食量、动物生产性能及空气质量产生负面影响。除了进行农场调查外，还开展了3项实验室试验，以研究空气（通过延迟密封或厌氧储存期间的空气渗入）、温度（20和35℃）以及各类添加剂[苯甲酸钠和丙酸钠混合物（SBSP）或苯甲酸钠和山梨酸钾混合物（SBPS）；甲酸和丙酸缓冲混合物（FAPA）；同型发酵接种剂（LAB）]的影响。经过添加剂处理后，将切碎的全株玉米装入1.5升玻璃罐中并储存数月。对于有空气渗入的处理，使用盖子和罐体有孔的玻璃罐。2009年的农场调查显示，乳酸、乙酸、乙醇、正丙醇和1,2 - 丙二醇浓度存在很大差异。尽管在所有青贮饲料中均检测到乙酯，但乳酸乙酯的平均浓度高于乙酸乙酯（分别为474和38mg/kg干物质）。在青贮试验中，由于存在许多相互作用，未观察到所测试因素对分析参数有明确的影响。无添加剂的延迟青贮降低了乳酸产量，但在一项试验中增加了乙酸产量且对乙醇无影响。延迟密封对酵母数量及有氧稳定性的影响在各试验中差异很大。在一项试验中测试的发酵期间空气渗入并未改变乳酸产量，但导致延迟密封青贮饲料中的乙酸更多，乙醇比立即密封的未处理青贮饲料中的更多。乙醇产量增加与酵母数量增多有关。高温储存导致乳酸和正丙醇含量降低，并且观察到乙醇产量有降低趋势。添加剂FAPA始终导致乙醇增加和正丙醇水平降低，对酵母数量及有氧稳定性无影响。当添加剂SBSP和SBPS降低正丙醇和乙醇时，酵母数量也减少。乙酯形成与乙醇形成密切相关，与相应酸的形成相关性较小。
