Hannah S M, Paterson J A, Williams J E, Kerley M S
University of Missouri, Columbia 65211.
J Anim Sci. 1990 Aug;68(8):2536-45. doi: 10.2527/1990.6882536x.
Three digestion experiments and one growth experiment were conducted to determine site, extent and ruminal rate of forage digestion and rate and efficiency of gain by cattle offered alfalfa haylage supplemented with corn or dry corn gluten feed (CGF). In Exp. 1, eight steers were fed alfalfa haylage-based diets with substitution of corn for 0, 20, 40 or 60% of haylage in a 4 X 4 latin square. Increasing dietary corn substitution increased (P less than .05) OM, NDF and ADF digestion by steers but decreased (P less than .05) rate of in situ alfalfa DM digestion. In Exp. 2, five heifers were fed alfalfa haylage-based diets with increasing dietary levels of CGF in a 5 X 5 latin square. Increasing dietary CGF increased (P less than .05) OM, NDF and ADF digestion by heifers. In Exp. 3 and 4, cattle were fed alfalfa haylage-based diets containing either 20 or 60% corn or CGF. In Exp. 3, supplementation increased (P less than .05) OM and NDF digestion but level X supplement source interaction (P less than .05) occurred, with added CGF increasing OM and NDF digestion more than added corn. In Exp. 4, supplementation improved (P less than .05) DM intake, daily gain and feed efficiency. Dry matter intake and daily gain were greater (P less than .05) for 60% supplementation than for 20% supplementation. Overall, whereas increasing the level of dietary supplement increased (P less than .05) OM, NDF and ADF digestion, only corn addition decreased (P less than .05) rate of in situ alfalfa DM digestion. Daily gains and feed efficiencies were similar in cattle fed either corn or CGF with alfalfa haylage.
进行了三项消化试验和一项生长试验，以确定饲喂添加玉米或干玉米蛋白粉（CGF）的苜蓿青贮饲料的牛的草料消化部位、程度和瘤胃消化率，以及增重速率和效率。在试验1中，八头阉牛饲喂以苜蓿青贮为基础的日粮，按照4×4拉丁方设计，用玉米替代0%、20%、40%或60%的青贮饲料。日粮中玉米替代量增加，阉牛对有机物质（OM）、中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）的消化率提高（P<0.05），但苜蓿干物质原位消化率降低（P<0.05）。在试验2中，五头小母牛按照5×5拉丁方设计，饲喂以苜蓿青贮为基础的日粮，日粮中CGF水平逐渐增加。日粮中CGF增加，小母牛对OM、NDF和ADF的消化率提高（P<0.05）。在试验3和试验4中，牛饲喂含有20%或60%玉米或CGF的以苜蓿青贮为基础的日粮。在试验3中，添加物提高了（P<0.05）OM和NDF的消化率，但水平×添加物来源存在交互作用（P<0.05），添加CGF比添加玉米对OM和NDF消化率的提高更多。在试验4中，添加物改善了（P<0.05）干物质采食量、日增重和饲料效率。60%添加水平的干物质采食量和日增重高于（P<0.05）20%添加水平。总体而言，日粮添加水平增加，OM、NDF和ADF的消化率提高（P<0.05），但只有添加玉米降低了（P<0.05）苜蓿干物质原位消化率。饲喂添加玉米或CGF的苜蓿青贮饲料的牛，日增重和饲料效率相似。
