Coffey K P, Moyer J L, Lomas L W, Turner K E
Southeast kansas Branch Experiment Station, Parsons 67357.
J Anim Sci. 1991 Jan;69(1):423-8. doi: 10.2527/1991.691423x.
Although esophageal extrusa is the most readily accepted representation of forage consumed by grazing ruminants, esophageal sampling is demanding from the standpoint of animal care and maintenance and extrusa processing. This experiment was conducted with a split-plot design to evaluate the effects of pasture type, pasture sampling technique and drying method on estimation of grazed forage composition. Ten esophageally fistulated steers grazed pastures of either tall fescue (Festuca arundinacea Schreb.) or tall fescue interseeded with ladino clover (Trifolium repens L.); steers were closely observed during four collection periods to determine their exact grazing location. Forage samples were collected either directly from the esophageal fistula (E) or hand-gathered (HG) from the immediate perimeter of the grazed area. Samples of E and HG from each steer were divided and oven-dried at 40 degrees C or lyophilized. Fescue samples had lower (P less than .01) N and ADF N concentrations than fescue-ladino clover samples, and E-collected fescue samples had lower (P less than .05) in vitro digestible OM than E-collected fescue-ladino clover samples. Sampling x drying method interactions were detected (P less than .01) for OM, NDF, ADF, hemicellulose (HEMI), ADL, alkaline peroxide lignin (APL), ADFN and indigestible ADF (IADF). Oven-dried E had higher (P less than .05) NDF, ADF, HEMI, ADL, APL and ADF N than lyophilized E; ADF N and IADF were higher from oven-dried HG than from lyophilized HG. In vitro digestible OM was not modified by oven drying. Hand-gathered samples, whether lyophilized or oven-dried, did not simulate E dried by lyophilization. Standardized collection techniques and drying procedures should be implemented to minimize damage to fibrous components.
尽管食管食糜是反刍动物放牧时所采食草料最容易被接受的表现形式，但从动物护理与饲养以及食糜处理的角度来看，食管采样要求很高。本试验采用裂区设计，以评估牧场类型、牧场采样技术和干燥方法对放牧草料组成估计的影响。十头装有食管瘘管的阉牛放牧于高羊茅（Festuca arundinacea Schreb.）或混播拉迪诺三叶草（Trifolium repens L.）的高羊茅牧场上；在四个采集期密切观察阉牛，以确定其确切放牧位置。草料样本要么直接从食管瘘管采集（E），要么从放牧区域周边手工采集（HG）。每头阉牛的E和HG样本被分开，在40℃下烘干或冻干。高羊茅样本的氮（N）和酸性洗涤纤维氮（ADF N）浓度低于高羊茅 - 拉迪诺三叶草样本，且通过E采集的高羊茅样本的体外可消化有机物质（OM）低于通过E采集的高羊茅 - 拉迪诺三叶草样本（P < 0.05）。对于OM、中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）、半纤维素（HEMI）、酸性洗涤木质素（ADL）、碱性过氧化物木质素（APL）、ADF N和不可消化ADF（IADF），检测到采样×干燥方法的交互作用（P < 0.01）。烘干的E的NDF、ADF、HEMI、ADL、APL和ADF N高于冻干的E（P < 0.05）；烘干的HG的ADF N和IADF高于冻干的HG。体外可消化OM不受烘干影响。手工采集的样本，无论冻干还是烘干，都不能模拟冻干的E。应采用标准化的采集技术和干燥程序，以尽量减少对纤维成分的损害。
