Effect of dehydration on ruminal degradability of lucerne

Abstract

The effects of industrial dehydration and a subsequent compression at high pressures on rumen degradability of lucerne were determined in 3 samples obtained at harvest or after the process of dehydration and compression of this forage. Rumen degradability of dry matter (DM) and nitro- gen (N) was determined by the nylon bag technique in 3 ruminally cannulated wethers. Dehydration reduced effective DM degradability (from 63.4 to 59.4%), which was associated with an increase of both the rumen undegradable fraction (from 30.5 to 33.4%) and the lignin content (from 65.7 to 77.9 g.kg -1 of DM). Effective degradability of N was also reduced by dehydration (from 82.7 to 77.7%), mainly by a decrease in the degradation rate (from 30.8 to 12.4% .h -1 ). The compression process produced a small but significant increase of the solubility of both DM and N, which did not alter the values of effective degradability. lucerne / dehydration / high pressure compression / rumen degradability