Department of Dairy Science, Virginia Tech, Blacksburg 24061.
Department of Dairy Science, Virginia Tech, Blacksburg 24061.
J Dairy Sci. 2018 Jul;101(7):6150-6154. doi: 10.3168/jds.2018-14512. Epub 2018 Apr 19.
The objective of this study was to compare ruminal starch disappearance rates of hull-less barley, hulled barley, and corn grains. Five different genotypes were used for each of the 2 barley types. In addition, each of these genotypes was grown in 2 different locations and years, resulting 10 independent barley samples for each of the 2 barley grain types. Five different genotypes of corn grain were obtained from a commercial seed company. After being ground to pass through a 4-mm screen of a cutter mill, 3.6 g of each grain was placed into a porous bag, which was then incubated in the rumen of 2 ruminally cannulated cows for 0, 4, 8, 12, 24, and 48 h. Corn grains had greater instant ruminal starch disappearances than barley grains (22.4 and 8.2%, respectively). Instant ruminal starch disappearances did not differ between hulled and hull-less barley grains. Ruminal starch fractional disappearance rates were greatest for hulled barley grains, moderate for hull-less barley grains, and lowest for corn grains (15.3, 13.9, and 7.1%/h, respectively). Ruminal starch half-life was shortest for hulled and hull-less barley grains (4.4 h) and longest for corn grains (6.6 h). Ruminal starch half-life did not differ between hulled barley and hull-less barley grains. In conclusion, using a holistic experimental design and statistical analysis, this study showed that starch from hull-less barley grains has a ruminal half-life similar to that of hulled barley grains and shorter than that of corn grains.
本研究的目的是比较无壳大麦、有壳大麦和玉米粒的瘤胃淀粉消失率。每种 2 种大麦类型使用 5 个不同的基因型。此外，这些基因型中的每一种都在 2 个不同的地点和年份种植，导致 2 种大麦类型的每个都有 10 个独立的大麦样本。5 种不同基因型的玉米来自商业种子公司。在通过切割机的 4 毫米筛网粉碎后，将 3.6 克每种谷物放入多孔袋中，然后将其在 2 个瘤胃切开的奶牛的瘤胃中孵育 0、4、8、12、24 和 48 小时。玉米粒的即时瘤胃淀粉消失率高于大麦粒（分别为 22.4%和 8.2%）。有壳和无壳大麦粒之间的即时瘤胃淀粉消失率没有差异。瘤胃淀粉的分数消失率以有壳大麦粒最高，无壳大麦粒中等，玉米粒最低（分别为 15.3%、13.9%和 7.1%/h）。瘤胃淀粉半衰期最短的是有壳和无壳大麦粒（4.4 小时），最长的是玉米粒（6.6 小时）。有壳和无壳大麦粒之间的瘤胃淀粉半衰期没有差异。总之，使用整体实验设计和统计分析，本研究表明无壳大麦粒中的淀粉的瘤胃半衰期与有壳大麦粒相似，短于玉米粒。
