Randby A T, Selmer-Olsen I, Baevre L
Department of Animal Science, Agricultural University of Norway, Hellerud, Skjetten, Norway.
J Dairy Sci. 1999 Feb;82(2):420-8. doi: 10.3168/jds.S0022-0302(99)75248-3.
A crossover study was performed using 24 dairy cows to investigate whether pure ethanol in concentrations that could be found in well-fermented silages influenced milk composition or flavor. Cows were fed a standard ration of well-fermented grass silage for ad libitum intake and high moisture barley and a protein concentrate in restricted amounts. A daily dose of ethanol (600 g) was divided into three meals/d and fed with grass silage. When cows received ethanol, milk yields decreased slightly, but milk fat and protein concentrations increased so that energy-corrected milk yield increased by 0.9 kg/d. Milk concentrations of lactose and urea decreased, concentrations of ethanol and acetone increased, concentrations of free fatty acids increased slightly, and alpha-tocopherol concentrations were unaffected. The proportion of palmitic acid in milk fat increased, and the proportion of unsaturated acids decreased. Organoleptic milk quality was reduced because of an increase in milk tainted by feed flavors. The off-flavor could not be attributed solely to the ethanol transmitted to the milk. Precautions should be taken to avoid extensive production of ethanol during fermentation of grass silage and other feeds that are to be fed to dairy cows.
采用交叉试验，使用24头奶牛研究在优质发酵青贮饲料中可能出现的纯乙醇浓度是否会影响牛奶的成分或风味。给奶牛自由采食优质发酵青草青贮饲料的标准日粮，并限量饲喂高水分大麦和蛋白质浓缩料。将每日乙醇剂量（600克）分为三餐，与青草青贮饲料一起饲喂。当奶牛摄入乙醇时，产奶量略有下降，但乳脂和蛋白质浓度增加，因此能量校正后的产奶量每天增加0.9千克。牛奶中乳糖和尿素的浓度降低，乙醇和丙酮的浓度增加，游离脂肪酸的浓度略有增加，α-生育酚浓度未受影响。乳脂中棕榈酸的比例增加，不饱和酸的比例降低。由于受饲料风味污染的牛奶增加，感官牛奶质量下降。异味不能仅仅归因于传递到牛奶中的乙醇。应采取预防措施，避免在青草青贮饲料和其他喂给奶牛的饲料发酵过程中大量产生乙醇。
