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 nitrogen (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