Hoffman P C, Combs D K, Brehm N M, Welch D A
Department of Dairy Science, University of Wisconsin, Madison 53706, USA.
J Dairy Sci. 1997 Dec;80(12):3308-15. doi: 10.3168/jds.S0022-0302(97)76306-9.
The objective of this study was to compare utilization of red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) by lactating dairy cows. Red clover and alfalfa were harvested and conserved as silage at two maturities in 2 consecutive yr. Each year, diets containing experimental forages and supplemental grain were fed to 16 multiparous Holstein cows in early lactation in a replicated 4 x 4 Latin square lactation trial. Lactation performance and nutrient intake responses caused by forage type (red clover vs. alfalfa), maturity (early vs. late), and equivalent acid detergent fiber (ADF) content (yr 1, late alfalfa vs. late red clover; yr 2, early alfalfa vs. late red clover) were compared. Milk yield was not different between cows fed red clover or alfalfa in yr 1, but milk yield was higher for cows fed red clover in yr 2. When cows were fed alfalfa and red clover with similar ADF content, the milk yield of cows fed red clover was lower than that of cows fed alfalfa in yr 1, and milk yields were similar between cows fed alfalfa and red clover in yr 2. Milk protein yield and percentage were lower for cows fed red clover in yr 1 and 2, respectively. Intake of ADF and neutral detergent fiber was lower for cows fed red clover in both years. When red clover contained the same ADF content as did alfalfa, cows fed red clover ate less ADF, neutral detergent fiber, and dry matter, resulting in lower milk yield potential.
本研究的目的是比较泌乳奶牛对红三叶草（Trifolium pratense L.）和苜蓿（Medicago sativa L.）的利用情况。连续两年在两个成熟阶段收获红三叶草和苜蓿并制成青贮饲料。每年，在重复的4×4拉丁方泌乳试验中，将含有试验性牧草和补充谷物的日粮饲喂给16头初产荷斯坦奶牛。比较了牧草类型（红三叶草与苜蓿）、成熟度（早期与晚期）以及等量酸性洗涤纤维（ADF）含量（第1年，晚期苜蓿与晚期红三叶草；第2年，早期苜蓿与晚期红三叶草）对泌乳性能和养分摄入的影响。第1年，饲喂红三叶草或苜蓿的奶牛产奶量没有差异，但第2年饲喂红三叶草的奶牛产奶量更高。当给奶牛饲喂ADF含量相似的苜蓿和红三叶草时，第1年饲喂红三叶草的奶牛产奶量低于饲喂苜蓿的奶牛，而第2年饲喂苜蓿和红三叶草的奶牛产奶量相似。第1年和第2年，饲喂红三叶草的奶牛乳蛋白产量和百分比分别较低。两年中，饲喂红三叶草的奶牛ADF和中性洗涤纤维摄入量均较低。当红三叶草的ADF含量与苜蓿相同时，饲喂红三叶草的奶牛ADF、中性洗涤纤维和干物质摄入量较少，导致产奶潜力较低。
