Karsli M A, Russell J R, Hersom M J
Department of Animal Science, Iowa State University, Ames 50011, USA.
J Anim Sci. 1999 Nov;77(11):2873-82. doi: 10.2527/1999.77112873x.
Berseem clover hay was compared to alfalfa hay provided at 0, 25, and 50% of the diet DM in mixtures with corn crop residues to wether lambs. Berseem clover hay had lower (P < .05) concentrations of NDF, ADF, and CP than alfalfa hay. The digestibility of DM, DMI, and N balance did not differ (P > .05) between diets containing alfalfa hay or berseem clover hay. To evaluate stockpiled berseem clover as a supplement for grazed corn crop residues, berseem clover and oats were incorporated into a corn-corn-oat/berseem clover crop rotation for 3 yr in replicated 6.1-ha fields. Two cuttings of oat-berseem clover hay were harvested each summer before forage was stockpiled for winter grazing. After corn grain harvest, multiparous and primiparous crossbred cows in midgestation were allotted to each field at 1.01 ha/cow to strip-graze corn crop residues with or without stockpiled berseem clover or allocated to replicated drylots for 98 to 140 d. Each group was offered alfalfa-grass hay as large bales to maintain a mean body condition score of 5 on a 9-point scale. Mean rates of total and digestible OM disappearance from grazed and ungrazed field areas of berseem clover and corn crop residues did not differ over the 3 yr. In vitro organic matter disappearance (IVOMD) tended to decrease more rapidly (P = .13) and NDF and ADF concentrations increased more rapidly (P < .05) in berseem clover than in corn crop residues. Seasonal BW change did not differ (P > .05) between winter management systems in any year, and seasonal body condition score changes did not differ (P > .05) between cows grazing corn crop residues and berseem clover and those maintained in a drylot in yr 2 and 3. Cows grazing corn crop residues with or without berseem clover required less (P < .05) hay than those maintained in drylot. Although the effects of berseem clover hay supplementation on the intake and digestibility of corn crop residues do not differ from alfalfa hay, the nutritional value of stockpiled berseem clover decreases rapidly during winter, limiting its value as a standing supplement for corn crop residues in late winter.
将埃及三叶草干草与苜蓿干草进行比较，在与玉米作物残茬的混合物中，以日粮干物质的0%、25%和50%的比例提供给阉羊。埃及三叶草干草的中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）和粗蛋白（CP）浓度低于苜蓿干草（P < 0.05）。含有苜蓿干草或埃及三叶草干草的日粮之间，干物质消化率、干物质采食量和氮平衡没有差异（P > 0.05）。为了评估堆存的埃及三叶草作为放牧玉米作物残茬的补充饲料，在6.1公顷的重复试验田中将埃及三叶草和燕麦纳入玉米-玉米-燕麦/埃及三叶草作物轮作中，为期3年。每年夏天在储存草料以供冬季放牧之前，收割两茬燕麦-埃及三叶草干草。玉米籽粒收获后，将处于妊娠中期的经产和初产杂交母牛以每头牛1.01公顷的密度分配到每个试验田，以条带放牧的方式放牧有或没有堆存埃及三叶草的玉米作物残茬，或者分配到重复的干栏舍中饲养98至140天。每组都提供苜蓿-禾本科干草大捆，以在9分制下将平均体况评分维持在5分。在3年期间，埃及三叶草和玉米作物残茬的放牧和未放牧区域的总有机物质和可消化有机物质消失的平均速率没有差异。在体外，埃及三叶草中的有机物质消失（IVOMD）往往比玉米作物残茬下降得更快（P = 0.13），NDF和ADF浓度增加得更快（P < 0.05）。在任何一年中，冬季管理系统之间的季节性体重变化没有差异（P > 0.05），在第2年和第3年，放牧玉米作物残茬和埃及三叶草的母牛与饲养在干栏舍中的母牛之间的季节性体况评分变化也没有差异（P > 0.05）。放牧有或没有埃及三叶草的玉米作物残茬的母牛比饲养在干栏舍中的母牛需要的干草更少（P < 0.05）。虽然补充埃及三叶草干草对玉米作物残茬的采食量和消化率的影响与苜蓿干草没有差异，但堆存的埃及三叶草的营养价值在冬季迅速下降，限制了其作为冬末玉米作物残茬常备补充饲料的价值。
