The use of triticale (X Triticosecale Wittmack) in dairy-cropping systems has expanded greatly in recent years, partly to improve land stewardship by providing winter ground cover. Our objective was to establish relationships relating indices of nutritive value with growth stage or accumulated growing degree days >5°C for triticale forages grown in central Wisconsin. Replicated 3.7-m × 9.1-m plots were established following removal of corn for silage (fall 2015) and soybeans (fall 2016) and then harvested at various growth stages the following spring. Plants were assigned a numerical growth stage based on a linear staging system suitable for use as an independent regression variable. Response variables [e.g., dry matter (DM) yield, indices of nutritive value, and parameters from in vitro DM disappearance kinetics] were regressed on growth stage and growing degree days using linear, quadratic, cubic, or quartic models. For spring 2016, the mean DM yield at the boot stage (3,804 kg of DM/ha) was only 30% of that observed at the soft dough stage of growth (12,642 kg of DM/ha). Although yields were reduced during spring 2017, primarily due to spring flooding, the relationship between respective yields at these growth stages was similar (1,453 vs. 5,399 kg of DM/ha). Regressions of DM yield (kg/ha) on growth stage for 2016 were explained by a cubic model (Y = 0.0663x³ − 9.44x² + 595x − 9,810) compared with a simple linear response for 2017 (Y = 103x − 3,024); in both cases, coefficients of determination were very high (R² ≥ 0.934). Many nutritional and in vitro DM disappearance characteristics were affected by the juxtaposition and balance of 2 generally competing factors: (1) increased concentrations of structural plant fiber coupled with concurrent lignification as plants matured and (2) the accumulation of highly digestible carbohydrate during seed head development. A comparison of respective energy yields between the boot and soft dough stages of growth for 2016 (2,488 vs. 8,141 kg of total digestible nutrients/ha) and 2017 (1,033 vs. 3,520 kg of total digestible nutrients/ha) suggests that yields of energy are greater at soft dough stage and are mostly driven by DM yield. An informed harvest management decision for lactating cows may still favor a boot-stage harvest because of superior nutritional characteristics, a need to plant double-cropped corn expeditiously, or both. Harvest timing of triticale forages for other livestock classes would appear to be more flexible, but prioritizing a subsequent double crop may reduce the effects on DM yield to a secondary consideration.

小黑麦（X Triticosecale的使用近年来，乳品作物系统中的Wittmack有了很大的发展，部分是通过提供冬季地面覆盖来改善土地管理。我们的目标是建立在威斯康星州中部种植的黑小麦草的营养价值指标与生长阶段或累积生长天数> 5°C的关系。在去除青贮玉米（2015年秋季）和大豆（2016年秋季）之后，建立了3.7米×9.1米的重复样地，然后在第二年春季的各个生长阶段收获。根据适合用作独立回归变量的线性分期系统，为植物分配了一个数字生长阶段。响应变量[例如干物质（DM）的产量，营养价值指数以及体外DM消失动力学的参数]在生长阶段和生长天数中使用线性回归，二次，三次或四次模型。2016年春季，启动阶段的平均DM产量（3,804 kg DM / ha）仅是生面团生长期（12,642 kg DM / ha）的30％。尽管2017年春季单产减少，主要是由于春季洪水，但在这些生长期的各个单产之间的关系相似（1,453比5399千克DM /公顷）。用立方模型解释了2016年生长阶段DM产量（kg / ha）的回归（Y = 0.0663x 5,399千克DM /公顷）。用立方模型解释了2016年生长阶段DM产量（kg / ha）的回归（Y = 0.0663x 5,399千克DM /公顷）。用立方模型解释了2016年生长阶段DM产量（kg / ha）的回归（Y = 0.0663x³ − 9.44x ² + 595x − 9,810）与2017年的简单线性响应（Y = 103x − 3,024）相比；在这两种情况下，确定系数都很高（R ²≥0.934）。许多营养和体外DM的消失特征都受到2种普遍竞争因素的并置和平衡的影响：（1）随着植物的成熟，结构性植物纤维的浓度增加并同时木质化;（2）种子头期间高消化性碳水化合物的积累发展。比较2016年生面团和软面团生长期（2,488 vs.8,141 kg /年的总可消化营养素）和2017（1,033 vs.3,520 kg /年的总可消化营养素/公顷）之间的能量产量表明，能量的产量在软面团阶段更大，并且主要是由干物质的产量驱动的。由于优越的营养特性，对泌乳母牛进行明智的收割管理决定可能仍然有利于后期收获，需要快速种植双季玉米，或两者同时进行。对于其他牲畜类别，小黑麦草料的收获时机似乎更为灵活，但是优先考虑随后的双季作物可将对DM产量的影响降低至次要考虑因素。