Processing whole-plant corn silage with crop processing rolls on a pull-type forage harvester

Whole-plant corn silage (WPCS) was harvested with a pull-type forage harves ter equipped with crop processing rolls. Variables considered were crop mat urity; theoretical length-of-cut (TLC), processor roll speed difference and roll clearance. Whole-plant particle, whole cob and coarse fiber fractions , level of kernel breakage, and kernel fraction particle-size were used to quantify crop physical properties. Compared to unprocessed WPCs cut at 9.5 mm TLC, WPCS cut at 19 mm TLC and then processed had greater estimated surf ace area of the kernel fraction. The processed treatments at 1 TLC and 3 or 5 mm roll clearance required similar specific energy and produced similar harvesting rates compared to the control unprocessed treatment at 9.5 mm TL C. Feeding dairy cattle WPCS (similar to 33% of DMI) increased fat-correcte d milk yield by bout 4% and fat yield by about 2%. Compared to unprocessed WCPS cut at seven percentage units. Based on crop physical properties, harv ester energy requirements and dairy cattle lactation performance, the recom mended settings when harvesting WPCS with an on-board crop processor would be 29 mm TLC and 1 to 3 mm roll clearance.