US Dairy Forage Research Center, USDA-ARS, Marshfield, WI 54449, USA.
J Anim Sci. 2010 Jan;88(1):383-99. doi: 10.2527/jas.2009-2224. Epub 2009 Sep 11.
Throughout the Southern Great Plains, wheat is managed frequently as a dual-purpose crop, but this production paradigm is not necessarily applicable throughout other regions of the United States, and a wider array of management options can be considered for forage-only uses of cereal grains. Our objectives were to assess the fall-growth potential of wheat (Triticum aestivum L.), triticale (X Triticosecale Wittmack), and oat (Avena sativa L.) cultivars in Wisconsin, and then to further evaluate and compare the fiber composition and TDN of these fall-grown forages. For 2006, yields of DM for all cultivars increased quadratically (P < or = 0.048) over fall harvest dates, reaching a maximum of 3,967 kg/ha for Ogle oat. All oat cultivars exhibited stem elongation and also displayed a collective 2 to 1 yield advantage over vegetative wheat cultivars on the final (October 30) harvest date. Growing conditions were more favorable during 2007, and yields were improved for all cultivars. Yields of DM for all cultivars increased quadratically (P < or = 0.021) across harvest dates, and oat cultivars maintained the identical 2 to 1 yield advantage over wheat cultivars (6,275 vs. 3,203 kg/ha) that was observed for 2006. Triticale exhibited yields intermediate between oat and wheat during both years. Concentrations of NDF increased quadratically (P < or = 0.012) across harvest dates for all cultivars during both years of the experiment; however, these increases occurred primarily between mid September and early October with limited responses thereafter. Oat and triticale cultivars had greater (P < 0.001) concentrations of NDF than wheat cultivars on 5 of 6 harvest dates throughout the experiment. Estimates of TDN exhibited various polynomial responses to harvest date during 2006, but the magnitude of these changes was relatively small. During 2007, TDN declined linearly (P < or = 0.038) for grain-type oat, but no relationship with harvest date was observed for other cultivars (P > or = 0.072), including forage-type oat. Although TDN estimates generally were relatively static across harvest dates, the concentrations of truly digestible components constituting the total TDN pool were quite fluid. Generally, reductions of truly digestible CP were offset by increases in truly digestible nonfiber carbohydrate, truly digestible fiber, or both. The relatively stable energy densities for cereal-grain cultivars observed across harvest dates suggest that a broad window of opportunity exists for usage, including a single harvest as silage.
在美国的其他地区，小麦作为一种两用作物的这种生产模式不一定适用，因此可以考虑为谷物饲料的仅用作饲料的用途提供更广泛的管理选择。我们的目标是评估小麦（Triticum aestivum L.）、黑小麦（X Triticosecale Wittmack）和燕麦（Avena sativa L.）品种在威斯康星州的秋季生长潜力，然后进一步评估和比较这些秋季生长饲料的纤维成分和总可消化养分。对于 2006 年，所有品种的 DM 产量均随秋季收获日期呈二次曲线（P < or = 0.048）增加，奥格尔燕麦的最高产量达到 3967 kg/ha。所有燕麦品种均表现出茎伸长，并且在 10 月 30 日（最后一次）收获日期，与营养生长的小麦品种相比，燕麦品种具有 2 到 1 的产量优势。2007 年的生长条件更加有利，所有品种的产量都有所提高。所有品种的 DM 产量均随收获日期呈二次曲线（P < or = 0.021）增加，燕麦品种与小麦品种相比保持着 2 到 1 的产量优势（6275 比 3203 kg/ha），这与 2006 年观察到的结果相同。黑小麦在两年中均表现出介于燕麦和小麦之间的产量。在实验的两年中，所有品种的 NDF 浓度均随收获日期呈二次曲线（P < or = 0.012）增加。然而，这些增加主要发生在 9 月中旬至 10 月初，此后的反应有限。燕麦和黑小麦品种在实验的 6 次收获中的 5 次中，NDF 浓度均高于小麦品种（P < 0.001）。在 2006 年，TDN 的估计值对收获日期呈各种多项式反应，但这些变化的幅度相对较小。在 2007 年，谷物型燕麦的 TDN 呈线性下降（P < or = 0.038），但其他品种（P > or = 0.072），包括饲料型燕麦，与收获日期没有关系。尽管 TDN 估计值通常在收获日期之间相对稳定，但构成总 TDN 池的真正可消化成分的浓度却非常不稳定。一般来说，真正可消化 CP 的减少被真正可消化非纤维碳水化合物、真正可消化纤维或两者的增加所抵消。在收获日期之间观察到的谷物品种相对稳定的能量密度表明，存在广泛的使用机会，包括单一收获作为青贮饲料。
