DRY MATTER OBTAINIMENT METHOD AND CHEMICAL COMPOSITION OF ROUGHAGES

Abstract It was aimed determinate the influence of drying methods on nutritional composition of different roughages. The experimental material were four grass species (Urochloa brizantha cv. Marandu, Urochloa brizantha cv. MG4, Cynodon dactylon cv. Coastcross e Panicum maximum cv. Áries), one forage legume (Stylosanthes cv. Campo Grande) and two silages (Zea mays e Triticum aestivum cv. BRS Umbu). The drying methods were based on use of forced air oven or microwave oven. The experimental design were a 2 x 8 factorial arrangement (2 drying methods and 8 roughages) with 4 repetitions. There was no effect of drying method on roughages dry matter content. Microwave oven drying increased neutral detergent fiber. There was an interaction between drying method and evaluated roughage. Increased contents of crude protein (estilosante), neutral detergent insoluble nitrogen (Coastcross, MG4, Marandu e estilosante) and ether extract (MG4, estilosante e Áries) were observed when roughages were dried using microwave oven. The microwave oven usage is an alternative to obtain the dry matter content of roughages; however this technic may affect the sample composition.

摘要 本研究旨在明确干燥方式对不同粗饲料营养成分的影响。试验材料包含4种禾草（Urochloa brizantha cv. Marandu、Urochloa brizantha cv. MG4、Cynodon dactylon cv. Coastcross及Panicum maximum cv. Áries）、1种豆科饲草（Stylosanthes cv. Campo Grande）以及2种青贮饲料（Zea mays及Triticum aestivum cv. BRS Umbu）。干燥方式分为强制热风烘箱干燥法与微波炉干燥法。试验采用2×8因子设计（2种干燥方式与8种粗饲料），设置4次重复。干燥方式对粗饲料干物质含量无显著影响。微波炉干燥可提升中性洗涤纤维（neutral detergent fiber）含量。干燥方式与受试粗饲料间存在交互效应。当采用微波炉干燥粗饲料时，可观测到柱花草的粗蛋白（crude protein）、Coastcross、MG4、Marandu及柱花草的中性洗涤不溶性氮（neutral detergent insoluble nitrogen），以及MG4、柱花草及Áries的粗脂肪（ether extract）含量均有所升高。微波炉干燥法可作为获取粗饲料干物质含量的替代手段，但该技术可能会影响样品的营养组成。