关键词: 发酵饲料, 干秸秆, 气质联机, 生化变化

Abstract: A study of the biochemical changes induced by natural fermentation of dry cornstalk, wheat straw, and rice straw shows that the fermenting cornstalk smells sweet with pH value diminishing quickly and remaining down below 4.2 hereon. Thirteen volatile fermentation products emerge, chiefly ethanol, acetic acid, lactic acid, and glycerol which improve the fermenting quality. As for the wheat and rice straws, their textures are rude and substantial, the fermenting products smells bad and their pH values diminish insignificantly. The 20 or more kinds of volatile products of fermentation include limited concentrations of acetic acid and lactic acid but a lot more substances like butyric acid which impairs the fermentation quality. Usually, the content of water-soluble carbohydrates (WSC) in the fermenting stuff reflects in certain extent its quality. The pH value diminishes quickly at the beginning of the fermentation with WSC oozing, and remain the same amount in the later stage. When the WSC content is scarce at the initial stage of the fermentation, the pH value diminishes slowly while the WSC content tapers off.

Key words: Fermented feed, Dry stalk or straw, GCMS, Biochemical changes