Abstract
The introduction of new protein evaluation systems for ruminants presupposes means to measure the ruminal protein degradability of feeds (Burroughs, Nelson & Mertens, 1975; Royet al.1977; Vérité, Journet & Jarrige, 1979). One potentially useful method to get such estimates is the nylon bag technique (Mehrez & Ørskov, 1977). This method, however, does not take into account the flow of feed particles from the rumen. By adjusting rumen degradation results obtainedin saccowith the outflow of the feed from the rumen more accurate estimates of the actual degradability is possible (0ørskov & McDonald, 1979).