Winter variation in nutrient and fiber content and in vitro digestibility of gambel oak (Quercus gambellii) and big sagebrush (Artemisia tridentata) from diversified sites in Colorado.
Winter variation in nutrient and fiber content and in vitro digestibility of gambel oak (Quercus gambellii) and big sagebrush (Artemisia tridentata) from diversified sites in Colorado.
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科罗拉多州不同地点的甘贝尔橡树 (Quercus gambellii) 和大山艾 (Artemisia tridentata) 的营养成分和纤维含量以及体外消化率的冬季变化。
DOI：
10.2307/3898133
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
D. C. Bowden
中科院分区：
文献类型：
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作者：
R. C. Kufeld;M. Stevens;D. C. Bowden
营养和纤维含量和体外可消化干物质（IVDDM）进行了测定，在甘贝尔橡树（甘贝尔栎）和大山艾（蒿）样本收集在1月从9个地理区域广泛分布在整个西部的科罗拉多，并代表三种植被类型。两种植物的干物质含量、IVDDM和大多数细胞及细胞壁成分的区域间变异系数均小于10%。变化似乎很小，足以允许应用一个适当选择的，恒定的值，这将反映冬季营养成分，纤维含量或消化率的这些物种，无论在哪里收集在科罗拉多，在调查中，冬季营养状况的大型游戏牧场正在估计管理的目的。大的游戏范围的管理应包括营养和纤维含量和现有的饲料植物在关键的冬季期间的消化率的知识。构成冬季大型猎物饮食的草料种类必须具有足够高的消化率和营养含量，以满足动物的最低需求。目前评估冬季牧场营养状况的最新技术包括对每种牧草或饲料混合物进行化学分析，以确定消化率、纤维成分和营养成分。每次分析都是耗时且昂贵的。如果同时评估多个冬季牧场，则对每个牧场上的每种植物物种进行详细分析的时间和成本将过高。如果同一物种的植物之间的差异足够小，允许应用适当选择的常数来反映冬季营养成分，纤维含量和消化率的一个物种，无论在哪里收集，可以减少评估的成本范围。这样就没有必要对每一个有关牧场地区的个别物种的营养纤维或消化率水平进行取样。在某些情况下，仅仅确定一块牧场的综合营养水平高于某个最低值，而不是测量实际的综合营养水平，可能就足够了。植物中的养分含量水平受到多种因素的影响，包括季节、气候、天气、海拔、光照以及土壤成分，例如母质、质地、深度、养分含量、水分和温度（Laycock and Price 1970）。Cook和Harris（1950）得出结论，“饲料的营养成分受许多相互依赖的因素影响，结果是所有因素操作模拟器的累加或质量效应。作者分别是科罗拉多野生动物部野生动物研究员和野生动物技术员，地址：317 West前景Street，柯林斯堡，科罗拉多80526，以及科罗拉多州立大学统计学副教授，柯林斯堡，科罗拉多，80523。这项研究部分由联邦鱼类和野生动物恢复援助，科罗拉多项目W-126-R资助。作者感谢Dan Milchunas和Dan Raker在体外消化率试验中提供的帮助。1979年9月21日，曼尼托巴被接收。1981年3月，《管理学杂志》第34卷第2期。因此，只有在所有因素引起的变化都相当小的情况下，对每一物种使用恒定值才能提供总营养含量、纤维含量或消化率的适当近似值。本研究的目的是确定在广泛多样化的条件下，在不同的地理位置生长的个别范围的牧草品种的营养含量和消化率的变化程度。两个物种，甘贝尔橡树（栎甘贝利）和大山艾（蒿tridentata）的选择进行研究。由于难以根据田间亚种识别山艾属植物，为收集管理数据而进行的大多数大型狩猎冬季范围调查将仅在物种水平上测量饲料产量。因此，在这项研究中，大的山艾树收集包括所有亚种的A。tridentata，以确定物种内营养、纤维和消化率的变化程度，因为它发生在科罗拉多。
Nutrient and fiber content and in vitro digestible dry matter (IVDDM) were measured in Gambel oak (Quercus gambellii) and big sagebrush (Artemisia tridentata) samples collected during January from nine geographic areas distributed widely throughout the western half of Colorado, and representing three vegetation types. Coefficients of variation among areas were less than 10% in both species in dry matter content, IVDDM and most cell and cell wall components. Variation appears to be small enough to permit application of a suitably selected, constant value, which would reflect winter nutrient content, fiber content or digestibility of these species, regardless of where collected in Colorado, in surveys where winter nutritional status of big game rangelands is being estimated for management purposes. Management of big game range should include knowledge of the nutrient and fiber content and digestibility of existing forage plants during the critical winter period. Forage species which comprise winter big game diets must be high enough in digestibility and nutrient content to meet minimum animal requirements. The current state of the art for evaluating nutritional status of winter rangelands involves chemical analysis of each forage species or of diet mixes to determine percent digestibility, fiber composition, and nutrient content. Each analysis is time consuming and expensive. If a number of winter ranges were being evaluated simultaneously, the time and cost of a detailed analysis of each plant species on each range would be exorbitant. Costs of evaluating a number of ranges could be reduced if variation among plants of the same species was small enough to permit application of suitably selected constants to be used to reflect winter nutrient content, fiber content, and digestibility of a species regardless of where collected. This would render it unnecessary to sample nutrient fiber or digestibility levels of individual species on each rangeland area of interest. In some cases it may be adequate merely to determine that the composite nutrient level for a piece of rangeland is above some minimum value rather than to measure actual composite nutrient levels. Nutrient content levels in plants are influenced by numerous factors, including season of year, climate, weather, elevation, and light and soil constituents such as parent material, texture, depth, nutrient content, moisture, and temperature (Laycock and Price 1970). Cook and Harris (1950) concluded that “the nutrient content of forage is influenced by many interdependent factors and the result is the additive or mass effect of all factors operating simulAuthors are, respectively, wildlife researcher and wildlife technician, Colorado Division of Wildlife, 317 West Prospect Street, Fort Collins, Colorado 80526, and associate professor of statistics, Colorado State University, Fort Collins, Colorado, 80523. This study was financed in part by Federal Aid in Fish and Wildlife Restoration, Colorado Project W-126-R. The authors gratefully acknowledge Dan Milchunas and Dan Raker for their assistance in conducting in vitro digestibility trials. Manuscript received September 21, 1979. JOURNAL OF RANGE MANAGEMENT 34(2), March 1981 taneously.” Therefore, use of a constant value for each species will provide an adequate approximation of the overall nutrient content, fiber content, or digestibility only if variation due to all factors is reasonably small. The purpose of this study was to determine extent of variation in nutrient content and digestibility of individual range forage species growing under widely diversified conditions and in different geographic locations. Two species, Gambel oak (Quercus gambellii) and big sagebrush (Artemisia tridentata), were selected for study. Due to difficulty in identifying sagebrush plants according to subspecies in the field most big game winter range surveys conducted to collect management data would measure forage production only to the species level. Therefore, big sagebrush collections in this study included all subspecies of A. tridentata in an effort to determine the degree of variation nutrient, fiber, and digestibility within the species as it occurs within Colorado.