Beauchemin K A, McAllister T A, Dong Y, Farr B I, Cheng K J
Agriculture Canada, Research Station, Lethbridge, Alberta.
J Anim Sci. 1994 Jan;72(1):236-46. doi: 10.2527/1994.721236x.
A study was conducted to evaluate the effects of mastication on the physical breakdown and ruminal digestion of whole cereal grains by cattle. Three Hereford cows (initial BW 557 kg; SD, 17) surgically fitted with ruminal and esophageal fistulas were fed 5.5 kg/d (as-fed basis) of whole barley, corn, or wheat in an experiment designed as a 3 x 3 Latin square. Eating time and chews per kilogram of DM were greater (P < .10) for corn than for barley or wheat. Whole corn was substantially damaged after ingestive mastication, and the majority of kernels were broken into small pieces. Many barley and wheat kernels showed signs of dentition, but most kernels remained intact. Less saliva (P < .10) was added to whole wheat than to barley or corn during ingestive mastication. Cattle fed whole barley spent twice (P < .10) as long ruminating per kilogram of DM as those fed corn, with intermediate times for wheat. Less than 30% of the DM disappeared from unmasticated whole grains during 96 h of ruminal incubation. Ingestive mastication increased DM digestion to 53, 69, and 66% for barley, corn, and wheat, respectively. Mastication alters the kinetics of ruminal digestion of unprocessed cereal grains. Combined with the inherent protein and starch digestibilities of the grain, mastication affects the type and extent of processing required to optimize the utilization of cereal grains by cattle. Unlike barley and wheat, corn kernels are extensively damaged during ingestive mastication, reducing the need for physical processing.
开展了一项研究，以评估咀嚼对牛对全谷物的物理分解和瘤胃消化的影响。三头赫里福德奶牛（初始体重557千克；标准差17）通过手术安装了瘤胃和食管瘘管，在一项设计为3×3拉丁方的实验中，每头每天饲喂5.5千克（以风干基础计）的全大麦、玉米或小麦。玉米每千克干物质的采食时间和咀嚼次数比大麦或小麦更多（P < 0.10）。采食咀嚼后，全玉米受到了严重破坏，大多数玉米粒都破碎成了小碎片。许多大麦和小麦粒有磨损的迹象，但大多数颗粒仍保持完整。采食咀嚼时，添加到全小麦中的唾液比添加到大麦或玉米中的少（P < 0.10）。每千克干物质，饲喂全大麦的牛反刍时间是饲喂玉米的牛的两倍（P < 0.10），饲喂小麦的牛反刍时间介于两者之间。在瘤胃培养96小时期间，未咀嚼的全谷物中干物质消失量不到30%。采食咀嚼分别使大麦、玉米和小麦的干物质消化率提高到53%、69%和66%。咀嚼改变了未加工谷物瘤胃消化的动力学。结合谷物固有的蛋白质和淀粉消化率，咀嚼会影响优化牛对谷物利用所需的加工类型和程度。与大麦和小麦不同，玉米粒在采食咀嚼过程中受到广泛破坏，从而减少了物理加工的需求。
