Ruiz T M, Bernal E, Staples C R, Sollenberger L E, Gallaher R N
Dairy Science Department, University of Florida, Gainesville 32611, USA.
J Dairy Sci. 1995 Feb;78(2):305-19. doi: 10.3168/jds.S0022-0302(95)76639-5.
'Mott' dwarf elephantgrass, forage sorghum, 'Tifton 81' bermudagrass, and whole corn plant were stored as silage and fed as the only forage source in diets formulated to 31, 35, and 39% NDF. The 12 diets were fed for ad libitum intake as a TMR to midlactation Holstein cows, primarily to determine the effect of NDF concentration and forage source on DMI and milk production. Increased dietary NDF concentration linearly decreased DMI (3.69 to 3.35%) and OM intake (3.39 to 3.06%) as a percentage of BW and linearly increased NDF intake as a percentage of BW (1.15 to 1.32%). Production of milk (23.0 to 21.7 kg/d) and 4% FCM (20.7 to 19.6 kg/d) and percentage of milk protein (3.16 to 3.07%) decreased linearly as dietary NDF concentration increased. Cows fed dwarf elephantgrass silage or corn silage, which were higher quality forage sources based on greater rates and extents of fiber digestion, consumed more DM and produced more milk than cows fed sorghum silage or bermudagrass silage. Cows fed diets containing sorghum silage had the lowest DMI and milk production. Apparent digestibility of NDF and ADF from corn silage and dwarf elephantgrass silage was greater than that of sorghum silage and bermudagrass silage. In addition to dietary NDF concentration, digestibility of dietary fiber influences DMI and milk production.
“莫特”矮象草、饲用高粱、“蒂夫顿81”百慕大草和全株玉米作为青贮饲料储存，并作为唯一的粗饲料来源，用于配制中性洗涤纤维（NDF）含量分别为31%、35%和39%的日粮。这12种日粮以全混合日粮（TMR）的形式自由采食，饲喂处于泌乳中期的荷斯坦奶牛，主要目的是确定NDF浓度和粗饲料来源对干物质采食量（DMI）和产奶量的影响。日粮中NDF浓度增加，奶牛的DMI（从占体重的3.69%降至3.35%）和有机物采食量（从占体重的3.39%降至3.06%）呈线性下降，而NDF采食量占体重的百分比（从1.15%增至1.32%）呈线性增加。随着日粮中NDF浓度的增加，牛奶产量（从23.0千克/天降至21.7千克/天）、4%乳脂校正乳产量（从20.7千克/天降至19.6千克/天）以及乳蛋白百分比（从3.16%降至3.07%）呈线性下降。与饲喂高粱青贮或百慕大草青贮的奶牛相比，饲喂矮象草青贮或玉米青贮（基于更高的纤维消化率和消化程度，这两种是质量更高的粗饲料来源）的奶牛消耗更多的干物质，产奶量也更高。饲喂含高粱青贮日粮的奶牛DMI和产奶量最低。玉米青贮和矮象草青贮中NDF和酸性洗涤纤维（ADF）的表观消化率高于高粱青贮和百慕大草青贮。除了日粮NDF浓度外，膳食纤维的消化率也会影响DMI和产奶量。
