Two steel corrugated rolls turning at differential speeds were integrated in an experimental pull-type forage
harvester for crop processing. With a 12.7 mm theoretical length-of-cut setting, the processing rolls were used to treat
alfalfa at a 1 mm clearance between the rolls. Processing required 30% more total harvest energy (5.6 vs 4.3 kW·h/t dry
matter). Processing corn at a 4.5 mm clearance required 7% more energy (3.7 vs 3.5 kW·h/t DM). Mean particle length
was reduced by 13% in alfalfa and 15% in corn after processing. About 38% of the corn kernels were pulverized
(in particles smaller than 2 mm) by the processor; the remaining kernels were more broken than kernels in non-processed
corn. Samples of alfalfa and corn were immediately frozen after harvest (i.e., non fermented), subsequently thawed and
incubated in the rumen of fistulated cows to measure the rate of degradation. Processing increased the rapidly degradable
dry matter fraction of alfalfa but did not affect the overall, effective degradability. Processing increased the effective
degradability of corn dry matter by 3%.