College of Animal Science and Technology, Northeast Agricultural University , Harbin 150030, China.
Gushi Agriculture & Animal Husbandry Group Company, Ltd. , Harbin 150078, China.
J Agric Food Chem. 2017 May 24;65(20):4035-4043. doi: 10.1021/acs.jafc.7b00231. Epub 2017 May 12.
The objectives of this study were to investigate (1) nutritive values and biodegradation characteristics and (2) mid-IR spectroscopic features within the regions associated with carbohydrate functional groups (including cellulosic component (CELC), structural carbohydrate (STCHO), and total carbohydrate (CHO)) in different morphological fractions of corn stover. Furthermore, correlation and regression analyses were also applied to determine the relationship between nutritional values and spectroscopic parameters. The results showed that different morphological sections of corn stover had different nutrient supplies, in situ biodegradation characteristics, and spectral structural features within carbohydrate regions. The stem rind and ear husk were both high in fibrous content, which led to the lowest effective degradabilities (ED) among these stalk fractions. The ED values of NDF were ranked ear husk > stem pith > leaf blade > leaf sheath > whole plant > stem rind. Intensities of peak height and area within carbohydrate regions were relatively more stable compared with spectral ratio profiles. Significant difference was found only in peak area intensity of CELC, which was at the highest level for stem rind, followed by stem pith, leaf sheath, whole plant, leaf blade, and ear husk. Correlation results showed that changes in some carbohydrate spectral ratios were highly associated with carbohydrate chemical profiles and in situ rumen degradation kinetics. Among the various carbohydrate molecular spectral parameters that were tested in multiple regression analysis, CHO height ratios, and area ratios of CELC:CHO and CELC:STCHO as well as CELC area were mostly sensitive to nutrient supply and biodegradation characteristics in different morphological fractions of corn stover.
本研究的目的是调查（1）营养价值和生物降解特性，以及（2）与玉米秸秆不同形态部分中碳水化合物功能基团（包括纤维素成分（CELC）、结构性碳水化合物（STCHO）和总碳水化合物（CHO））相关的中红外光谱特征。此外，还应用了相关和回归分析来确定营养值和光谱参数之间的关系。结果表明，玉米秸秆的不同形态部分具有不同的养分供应、原位生物降解特性和碳水化合物区域的光谱结构特征。茎皮和穗壳都富含纤维，导致这些茎秆部分的有效降解率（ED）最低。NDF 的 ED 值排序为穗壳>茎髓>叶片>叶鞘>整株>茎皮。与光谱比谱相比，碳水化合物区域的峰高和峰面积强度相对更稳定。仅在 CELC 的峰面积强度方面发现了显著差异，其水平最高的是茎皮，其次是茎髓、叶鞘、整株、叶片和穗壳。相关结果表明，一些碳水化合物光谱比的变化与碳水化合物化学特征和原位瘤胃降解动力学高度相关。在多元回归分析中测试的各种碳水化合物分子光谱参数中，CHO 高度比以及 CELC:CHO 和 CELC:STCHO 的面积比以及 CELC 面积对玉米秸秆不同形态部分的养分供应和生物降解特性最为敏感。
