Microwave Heat Treatment Induced Changes in Forage Hay Digestibility and Cell Microstructure

• Main Authors: Md Safiqur Rahaman Shishir, Graham Brodie, Brendan Cullen, Ravneet Kaur, Ellie Cho, Long Cheng
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: Applied Sciences
• Subjects: thermal treatment; nutritional value; feed quality; SEM-IA; conserved forage
• Online Access: https://www.mdpi.com/2076-3417/10/22/8017

To investigate the effects of microwave (MW) treatment on hays nutritive value, five types of hay (50 g) were treated with MW for 0 (control), 20, 40, 60, and 80 s (0, 440, 880, 1320, and 1760 kJ kg⁻¹ of MW energy, respectively) and analyzed for nutritive value prior to scanning by an electron microscope to observe microstructure changes. The dry matter (DM) % of hays were increased with increasing treatment time (<i>p</i> < 0.001). The improved DM and digestible organic matter in the DM were recorded from MW treated lucerne (60 s), wheat (40 s), and canola (20 s) (<i>p</i> < 0.001), which might have been due to the MW ruptured cell wall. The MW energy required for maximal DM digestibility improvement was linearly related to control hay crude protein content (r² = 0.79; <i>p</i> < 0.001). Overall, the study showed MW treatment can increase some hays’ digestibility. In addition, the crude protein content from control hay may be a proxy to indicate DM digestibility improvement.