An automated pressure evaluation system (APES) for determining the fermentation characteristics of ruminant feeds

摘要

Many approaches have been taken to determine the nutritive value of ruminant feeds, most of which rely upon the measurement of end-points of digestibility and ignore the importance the kinetics of the process. A new method which enables the determination of rates of gas accumulation from in vitro fermentations was described recently (Theodorou ef al, 1994, Anim Feed Sci Technol, 48, 185 - 197). The procedure uses a pressure transducer to determine gas accumulation during the fermentation of feeds insubstrate-limited batch cultures inoculated with rumen digesta. One problem with the technique is the need for frequent readings during the initial (30 - 40 h) fermentation period, thus making it labour intensive. Experiments with different silages usingthe manual pressure transducer indicated that although differences could be detected, they were small when comparing different silages incubated over a long (5 d) fermentation period. The new automated technique overcomes this limitation, is more sensitive and allows a better description of the initial (8 h) rate of fermentation.