|Shinners, K. - UNIV. OF WISCONSIN-MADISO|
|Harrison, J. - WASHINGTON STATE UNIV.|
Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 29, 2005
Publication Date: January 23, 2006
Citation: Shinners, K.J., Mertens, D.R., Harrison, J. 2006. Processing whole-plant corn silage: machine, storage, and animal perspectives. In: Silage for Dairy Farms: Growing, Harvesting, Storing, and Feeding. Ithaca, NY: NRAES Publication 181. p. 140-157. Technical Abstract: Crop processors on forage harvesters increase the value of whole-plant corn silage by tearing and shredding plant stems and pulverizing kernels. These changes in physical form can improve ensiling, fiber utilization, starch digestion, feed intake and reduce feed sorting. Starch in corn kernels is the primary energy source in corn silage and maximizing its utilization is crucial to the nutritive value of corn silage, especially as maturity of the crop increases. In almost all studies reviewed, milk production and intake increased when dairy cattle were fed processed conventional corn hybrids. Typically, milk production increased 4 to 10% and intake increased 4 to 11%. Kernel fragmentation during processing is affected by processor roll clearance, length-of-cut and machine throughput as well as the maturity of the corn and possible differences among hybrids. Processor energy requirements are substantial so achieving the minimum level of processing needed to provide positive economic benefits is important. Producers must balance the choice of length-of-cut and processor roll clearance so that adequate crop physical properties are achieved without overtaxing the mechanical capabilities of the machine. Given the variation in harvesting conditions that can occur, there is a need for methods that quantify the extent of chopping and processing in specific situations. Laboratory methods have been developed that are available for assessing the extent of kernel fragmentation, the physical effectiveness of fiber, and the mean particle-size of corn silage. Results from these methods are useful in defining harvesting conditions that are acceptable and in adjusting dairy rations to maximize the use of processed corn silage. Dairy producers should target ¾ in. as the longest length-of-cut with an initial processor roll clearance of 0.12 in. If kernel breakage is not adequate, roller clearance should be reduced. If plugging occurs at the processor, the TLC should be reduced, which will result in a sacrifice of effective fiber to achieve adequate kernel fragmentation.