PLANT JUICES IN RELATION TO SILAGE FERMENTATION III. Effect of water activity of juice

Abstract

The water activity of juice available for fermentation, after breakdown of the cell walls during the ensiling of plant material, depends largely on the moisture content of the sample. Water activity increases with moisture content, but probably never becomes so high as seriously to limit lactic‐acid fermentation, although high moisture contents have other detrimental effects. With low moisture contents, the limited availability of the juice rather than its lowered water activity is most probably the factor primarily responsible for poor lactic‐acid production.

Methods for reduction of water soluble carbohydrate content in grass forages for horses

“…In the present study, haylage contained intermediate concentration of WSC compared to silage and hay, which is in agreement with previous findings of a restricted fermentation in haylage (Müller, 2005;Müller et al, 2008). The extent of fermentation, and therefore also the residual WSC concentration, depends on DM content and water activity of the haylage, as these are strong regulators of LAB activity (Greenhill, 1964) Losses of WSC have also been reported during hay-making due to plant respiration and microbial activity during drying (Rees, 1982). The magnitude of WSC losses in hay in the current experiment were small compared to WSC losses in silage, which contained the lowest concentration of WSC and its components.…”

Methane production from municipal refuse: A review of enhancement techniques and microbial dynamics

“…Halvadakis et al 43 concluded that leachate recycle increased the initial rate of gas production in a field-scale test cell that included anaerobic sewage sludge and calcium carbonate. Both Buivid and Kinman used calcium carbonate to neutralize refuse.…”

“…However, methane production was not always observed at low moisture contents (35%). Halvadakis et al 43 found moisture content to be one of the most critical variables controlling gas production in field-scale test cells. Using a modified biochemical methane potential assay, Bogner et al I2a stimulated methane production by increasing the moisture content of various refuse samples.…”

Silage and haylage for horses

“…However, the study comprised horses with no known feeding history, and the conclusion was based on several assumptions including the statement that silage fed to horses contains high amounts of acids, both added and naturally produced, as well as has a low pH (Gere & Dixon, ). This assumption should be questioned, as most horses are fed haylage which most often does not differ from hay in pH, and contains very low (if any) contents of acid fermentation products (Dawson et al., ; Driehuis & van Wikselaar, ; Field & Wilman, ; Finner, ; Gordon et al., ; Greenhill, ; Han et al., ; Jackson & Forbes, ; Müller & Udén, ; Müller et al., ; Nicholson et al., ; Pahlow & Weissbach, ). Furthermore, data from a small pilot study where the effect of forage type on pH value in the oral cavity of horses was investigated in a controlled study reported no differences in oral pH that were attributed to the type of forage fed (Ellevik, ).…”