Harvester Modifications to Alter Composition and Dry Matter of Corn-Silage

Abstract

Two common variants to conventional whole-plant corn silage (WP) are high-cut silage (HC) and snaplage (SNPL) which are harvested to alter DM content, fiber, and starch contents compared to WP silage. A conventional ear-snapper (ES) header is used to harvest SNPL which creates a low-fiber, starch-rich feed. However, the plant fractions in SNPL can dry quickly, creating issues with digestibility, palatability, fermentation, and aerobic stability. Stalk cut-off knives were added to the ES header to harvest more leaves and upper stalk to increase SNPL fiber content, yield and moisture. The DM content, yield and nutrient composition of the resulting material, referred to here as “toplage” (TPL), was between that of HC and SNPL. TPL yield averaged 72% to 77% of WP yield. Compared to HC or WP silages, TPL starch concentration was greater but the concentrations of fiber and lignin were less. To offset the loss in yield with harvesting only TPL, the biomass remaining after TPL was then harvested as a high-fiber roughage feed, referred to here as “stalklage” (STKL). STKL was either direct harvested or windrowed and then wilted to greater DM content before final harvest. The combination of TPL followed by STKL resulted in total yield 3% to 8% less than achieved with conventional WP silage. Windrowing increased STKL yield by collecting more leaves that had been dropped during TPL harvest compared to direct cutting, resulting in STKL with greater protein and lower fiber content. STKL had similar or better nutrient composition than reported values for corn stover harvested after grain harvest. Both TPL and STKL fermented well in mini-silos across a wide range of DM contents. The stalk cut-off knives are simple to adapt to the ES header, and by altering the number of knives, producers can easily change corn silage yield, DM content, and nutrient composition, offering an alternative to conventional SNPL or WP silages.