Harvesting corn snaplage is a viable alternative to rolled high-moisture shelled corn (RHMC). Snaplage generally contains the ear (cob and grain), husk and shank, and is harvested using a self-propelled forage harvester equipped with a snapper head and an onboard kernel processor. This allows for an earlier corn harvest, which proceeds more rapidly with kernel processing done in the harvester, rather than at the silo as is done with RHMC. However, snaplage has different nutritional qualities and harvest management considerations than RHMC.
- Snaplage harvesting and processing in a single operation compared with combining then grinding at silo for RHMC
- 10% to 25% increased dry matter (DM) yield per acre
- Earlier harvest than dry corn or RHMC, allowing for earlier manure application
- High ruminal starch digestibility if moisture is correct
- Additional source of fiber from husk, cob and shank
- Moisture must be between 32% to 45% for adequate packing; if too dry, packing is difficult and can cause spoilage
- Inconsistent product with variable amounts of stalk and leaves if snapper head not adjusted properly
- Harvest timing may be difficult to plan with custom harvesters, depending on corn silage harvest progress
- Potential for sorting of cob and husk if harvested too dry or not processed adequately
- Starch digestibility may be high after fermentation and impact rumen fermentation and milkfat content
Proper moisture content is needed for high nutrient content and adequate packing. Recommended snaplage moisture is between 32% and 40%. Kernel moisture of 28% to 35% is recommended with harvest beginning at blacklayer (34% to 35% kernel moisture) to maximize starch accumulation. Snaplage is typically 5% higher in moisture than the kernels due to the cob having greater moisture. Harvest at 28% to 35% kernel moisture will result in snaplage having 33% to 40% moisture. Harvesting at more than 40% moisture (less mature kernels) will reduce starch content.
Harvesting too dry (<32% moisture) will result in lower fiber digestibility, poor packing or fermentation, and sorting. Timely checking of kernel maturity and moisture is necessary to determine snaplage harvest timing. It is generally recommended to error on the wetter side of the range (35% to 40% moisture).
Proper set-up of the forage harvester is also needed. Theoretical length of cut (TLOC) should be made as small as possible by using all cutter knives and reducing feed roll speed. The kernel processor should be at 1 mm roll spacing with a higher speed differential of 40% to ensure kernel damage.
Storage and Feed-out
Snaplage storage will require greater capacity than RHMC due to greater yield and lower density. Typical densities of snaplage are 30 lb. to 40 lb. DM per cu. ft. Adequate feed-out is needed to maintain quality with a recommended minimum of 12" removed per day. Use of an inoculant with Lactobacillus buchneri can also reduce heating and help maintain feed-out quality.
Differences in Nutrient Composition
Snaplage typically has 10% more NDF and 10% less starch than RHMC. The additional fiber has good digestibility (55% to 70%) if snaplage is harvested in the proper moisture range. Snaplage energy content is usually 10% lower than RHMC due to more fibrous material. If too dry, digestibility of the cob will decrease and further lower the energy content of the snaplage.
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