Department of Animal Production and Animal Nutrition, University of São Paulo, Pirassununga, Brazil, 13635-900.
Department of Animal Science, Federal University of Viçosa, Viçosa, Brazil, 36570-900.
J Dairy Sci. 2022 Jul;105(7):5714-5722. doi: 10.3168/jds.2021-21682. Epub 2022 May 5.
Dry malt extract (DME) has been used in animal nutrition as an alternative source of rapidly fermentable carbohydrate. An experiment was conducted to evaluate the partial replacement of ground corn with DME in diets of dairy cows on apparent digestibility, ruminal fermentation, predicted rumen microbial protein supply, N excretion, serum urea-N concentration, and milk yield and composition. Twenty-eight Holstein cows (35.3 ± 5.88 kg/d milk yield and 148 ± 78 d in milk), 4 of which were rumen cannulated, were blocked according to the presence of rumen cannulas, parity, milk yield, and days in milk and enrolled into a crossover design experiment. Experimental periods lasted 21 d, of which the first 14 d were allowed for treatment adaptation and 7 d were used for data collection and sampling. Treatment sequences were composed of control (CON) or DME from barley (Liotécnica Tecnologia em Alimentos) replacing ground corn at 7.62% diet dry matter (~2 kg/d). Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc.) modeling the fixed effects of treatment, period, and their interaction, in addition to the random effect of animal. Ruminal fermentation data were analyzed as repeated measures including time and its interaction with treatment in the previous model as fixed effects. Treatments did not affect nutrient intake or feed sorting. Dry malt extract increased apparent digestibility of CP. Feeding DME decreased ruminal pH and molar percentage of butyrate and increased molar percentage of acetate. No treatment effects were detected for predicted rumen microbial protein supply or N excretion. Cows fed DME had lower serum urea-N concentration than CON cows. Dry malt extract increased yields of actual milk, 3.5% fat-corrected milk, fat, and protein, and improved feed efficiency (fat-corrected milk ÷ dry matter intake). Cows fed DME had lower milk urea nitrogen content in comparison with CON cows. Dry malt extract can partially replace ground corn in the diet while improving milk yield and feed efficiency.
干麦芽提取物（DME）已被用作动物营养中的替代快速发酵碳水化合物源。进行了一项实验，以评估在奶牛日粮中用 DME 部分替代玉米粉对表观消化率、瘤胃发酵、预测瘤胃微生物蛋白供应、N 排泄、血清尿素氮浓度以及产奶量和组成的影响。28 头荷斯坦奶牛（产奶量为 35.3±5.88kg/d，泌乳天数为 148±78d），其中 4 头为瘤胃插管，根据瘤胃插管的存在、胎次、产奶量和泌乳天数进行分组，采用交叉设计实验。实验期持续 21d，前 14d 允许处理适应，7d 用于数据收集和采样。处理顺序由对照（CON）或大麦的 DME（Liotécnica Tecnologia em Alimentos）组成，以 7.62%日粮干物质（~2kg/d）替代玉米粉。使用 SAS 的 MIXED 程序分析数据，该程序对处理、时期及其相互作用的固定效应进行建模，此外还对动物的随机效应进行建模。瘤胃发酵数据作为重复测量进行分析，包括时间及其与处理的相互作用，以及上述模型中的固定效应。处理对养分摄入或饲料分类没有影响。干麦芽提取物增加了 CP 的表观消化率。饲喂 DME 降低了瘤胃 pH 值和丁酸摩尔百分比，增加了乙酸摩尔百分比。预测的瘤胃微生物蛋白供应或 N 排泄没有检测到处理效果。饲喂 DME 的奶牛血清尿素氮浓度低于 CON 奶牛。干麦芽提取物增加了实际产奶量、3.5%校正乳脂产量、脂肪和蛋白质产量，并提高了饲料效率（校正乳脂产量÷干物质采食量）。与 CON 奶牛相比，饲喂 DME 的奶牛的牛奶尿素氮含量较低。干麦芽提取物可以在不降低产奶量和饲料效率的情况下，部分替代日粮中的玉米粉。
