Abstract

This study investigated the comparative effects of conventional hot-air oven heating (CHO), microwave heating (MW) and sealing effect on the nutritive value of lucerne hay. Equivalent energy (125 J.g⁻¹) was applied with a 1.1 kW of MW oven for 60 seconds (s) or a 3.06 kW CHO oven for 350 s. The required equivalent energy level was measured based on a preliminary calibration trial. Two heating method (CHO and MW) and sealing condition (SC) applied as treatment factors in this study. A two-way analysis of variance (P < 0.05) was used to measure the effect of different factors on some properties of lucerne hay. The dry matter (DM) percentage of lucerne hay was increased when MW treatments were applied on both sealed and non-sealed lucerne hay compared with the control. Both heating method and their interaction with SC had negative effects on crude protein (CP) percentage. DM digestibility (DMD) and Digestible organic matter in the DM (DOMD) were decreased by 9% and 5%, respectively, in the sealed MW group, compared with the sealed control. Neutral detergent fibre % also increased by 6% in the sealed MW group, compared with the sealed control group. However, no differences in acid detergent fibre % due to any heating method and/or SC were observed in this study. The mechanisms behind these changes require further exploration.

摘要

本研究比较了传统热风炉加热 (CHO)、微波加热 (MW) 和密封效果对苜蓿干草营养价值的影响。等效能量（125 Jg ^-1) 用于 1.1 kW MW 烘箱 60 秒 (s) 或 3.06 kW CHO 烘箱 350 秒。所需的等效能量水平是根据初步校准试验测量的。本研究采用两种加热方法（CHO 和 MW）和密封条件（SC）作为处理因素。采用双向方差分析（P < 0.05）来衡量不同因素对苜蓿干草某些特性的影响。与对照相比，当对密封和未密封的苜蓿干草进行 MW 处理时，苜蓿干草的干物质 (DM) 百分比增加。加热方法及其与 SC 的相互作用对粗蛋白 (CP) 百分比都有负面影响。与密封对照组相比，密封 MW 组的 DM 消化率 (DMD) 和 DM 中的可消化有机物 (DOMD) 分别降低了 9% 和 5%。与密封对照组相比，密封MW组的中性洗涤纤维百分比也增加了6%。然而，在本研究中没有观察到任何加热方法和/或 SC 导致的酸性洗涤剂纤维百分比差异。这些变化背后的机制需要进一步探索。