DePeters E J, Taylor S J
J Dairy Sci. 1985 Aug;68(8):2027-32. doi: 10.3168/jds.S0022-0302(85)81064-X.
Complete mixed, cubed diets containing corn or barley as the cereal component were fed to eight cows, four first lactation and four second or later lactation. Diets were fed for ad libitum intake in two periods of 21 d each. Percentages of milk fat, protein, lactose, and solids were not affected by corn or barley. Percentages of casein, whey, and nonprotein nitrogen were not different nor was proportion of total nitrogen represented as casein, whey, or nonprotein nitrogen for corn or barley diets. Production status, first lactation versus older cows, did not affect milk composition of casein, whey, and nonprotein nitrogen. Apparent digestibility of dry matter and energy was not different, but fiber digestibility was significantly lower for the barley diet. Intake of dry matter and digestible energy and yield of milk and milk constituents were not different. When diets were fed to rumen fistulated heifers, molar percentages of volatile fatty acids, total volatile fatty acid concentration, and pH of rumen fluid were not different for corn or barley diets.
将含有玉米或大麦作为谷物成分的完全混合、切碎的日粮喂给8头奶牛，其中4头处于头胎泌乳期，4头处于二胎或更晚的泌乳期。日粮分两个阶段自由采食，每个阶段21天。乳脂肪、蛋白质、乳糖和固体成分的百分比不受玉米或大麦的影响。酪蛋白、乳清和非蛋白氮的百分比没有差异，玉米或大麦日粮中酪蛋白、乳清或非蛋白氮占总氮的比例也没有差异。生产状态，即头胎泌乳期与老龄奶牛相比，不影响酪蛋白、乳清和非蛋白氮的乳成分。干物质和能量的表观消化率没有差异，但大麦日粮的纤维消化率显著较低。干物质和可消化能量的摄入量以及牛奶和牛奶成分的产量没有差异。当将日粮喂给瘤胃造瘘的小母牛时，玉米或大麦日粮的挥发性脂肪酸摩尔百分比、总挥发性脂肪酸浓度和瘤胃液pH值没有差异。
