RESUMO
Preliminary research has suggested that in vitro dry matter disappearance (DMD) of some poor quality animal fodder materials can be improved by microwave treatment. Laboratory scale experiments revealed that dry matter percentage of Lucerne hay increased by 1.7% as microwave treatment time increased from 0 to 80 seconds. The in vitro DMD of lucerne hay increased by 14.9% during the same microwave treatment. In addition it was also demonstrated that microwave treatment significantly increased starch digestion of oats compared to the control samples. These experiments were followed up with a larger sample experiment in which 25 kg bags of Lucerne fodder were treated for 7.5, 15, 22.5 or 30 minutes in an experimental 6 kW microwave chamber. Dry matter percentage increased by 7.2% as microwave treatment time increased from 0 to 30 minutes. Microwave treatment significantly increased DMD during an in vitro digestion study; however there were no significant differences between the various microwave treatment times. The 15 minute treatment resulted in the greatest increase in dry matter disappearance (5.9%). The crude protein retained in the digestion residues increased by 19.2% as microwave treatment increased from 0 to 30 minutes. These laboratory studies were followed up with an animal response study in which a Merino sheep group being fed the microwave treated lucerne gained 8.1% of their initial body weight by the end of the trial compared to a 0.4% increase in body weight for the control group.
