Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5A8, Canada.
Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2018 Feb 15;191:491-497. doi: 10.1016/j.saa.2017.10.040. Epub 2017 Oct 12.
Large scale of steam flaked corn has been used in dairy ration to maintain high milk production level. This study aimed to determine effects of steam flaking on processing-induced intrinsic molecular structure changes that were associated with rumen degradation kinetics and nutrients supply. The advanced vibrational molecular spectroscopy was applied to reveal the processing-induced intrinsic structure changes on a molecular basis. The rumen degradation kinetics and nutrient supply were determined using in situ approach in ruminant livestock system. Raw corn grain (RC) and steam flaked corn grain (SFC) were obtained from two different processing plants. The results showed that (1) Compared to RC, SFC had greater truly digestible non-fiber carbohydrate [tdNFC: 86.8 versus 78.0% dry matter (DM)], but lower truly digestible crude protein [tdCP: 7.7 versus 9.0% DM]. (2) The steam flaking increased (P<0.01) rumen degradable DM (RDDM) and starch (RDSt), but decreased (P<0.01) rumen degradable protein (RDP). (3) Molecular absorbance intensities of most carbohydrate biopolymers were greater in SFC (P<0.01), but protein amides associated molecular spectral intensities were lower (P<0.01) in SFC. (4). The molecular structure and nutrient interactive study showed that carbohydrate spectral intensities were positively (P<0.10) associated with RDDM and RDSt and protein amide spectral intensities were positively (P<0.10) associated with RDP. This results indicated that the steam flaking induced molecular structure changes had an interactive relationship with rumen degradation kinetics.
大规模的蒸汽压片玉米已被用于奶牛饲养中，以维持高水平的产奶量。本研究旨在确定蒸汽压片对加工引起的内在分子结构变化的影响，这些变化与瘤胃降解动力学和养分供应有关。先进的振动分子光谱学被应用于揭示加工引起的内在结构变化的分子基础。瘤胃降解动力学和养分供应是通过反刍家畜系统中的原位方法来确定的。原玉米籽粒（RC）和蒸汽压片玉米籽粒（SFC）是从两个不同的加工厂获得的。结果表明：（1）与 RC 相比，SFC 具有更高的真可消化非纤维性碳水化合物[tdNFC：86.8%比 78.0%干物质（DM）]，但真可消化粗蛋白[tdCP：7.7%比 9.0%DM]较低。（2）蒸汽压片增加了（P<0.01）瘤胃可降解 DM（RDDM）和淀粉（RDSt），但降低了（P<0.01）瘤胃可降解蛋白（RDP）。（3）大多数碳水化合物生物聚合物的分子吸收强度在 SFC 中更高（P<0.01），但与 SFC 相关的蛋白质酰胺分子光谱强度较低（P<0.01）。（4）分子结构和养分相互作用研究表明，碳水化合物光谱强度与 RDDM 和 RDSt 呈正相关（P<0.10），而蛋白质酰胺光谱强度与 RDP 呈正相关（P<0.10）。这些结果表明，蒸汽压片引起的分子结构变化与瘤胃降解动力学之间存在相互关系。
