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 harvester equipped with cropprocessing rolls. Variables considered were crop maturity, theoretical length-of-cut (TLC), processor roll speed differenceand roll clearance. Whole-plant particle size, whole cob and coarse fiber fractions, level of kernel breakage, and kernelfraction 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 whole-plant particle size, less whole cob fraction, fewerunbroken kernels, smaller kernel fraction particle size, and greater estimated surface area of the kernel fraction. Theprocessed treatments at 19 mm TLC and 3 or 5 mm roll clearance required similar specific energy and produced similarharvesting rates compared to the control unprocessed treatment at 9.5 mm TLC. Feeding dairy cattle WPCS (~33% ofDMI) increased fat-corrected milk yield by about 4% and fat yield by about 2%. Compared to unprocessed WPCS cut at9.5 mm TLC, WPCS cut at 19 mm TLC and processed with 1 mm roll clearance increased in situ DM disappearance byseven percentage units. Based on crop physical properties, harvester energy requirements and dairy cattle lactationperformance, the recommended settings when harvesting WPCS with an on-board crop processor would be 19 mm TLCand 1 to 3 mm roll clearance.