Why would a cattle feeder choose to feed one of these ingredients over the other, particularly when harvest date of earlage, snaplage and high-moisture corn overlap? As for many decisions on the farm, the choice to harvest corn at high moisture content with or without ear, cob and husks depends on harvest and processing equipment available, availability of other ingredients, and preference.
At harvest, both earlage and snaplage will yield greater tonnage than corn grain harvested at high moisture. The yield in tons of snaplage or earlage containing 75% or 80% corn grain, respectively, can be predicted by multiplying dry corn grain yield in bushels by 4.5% (earlage) to 5% (snaplage). Thus, a field expected to produce 200 bu/acre will likely produce 9 ton of earlage or 10 ton of snaplage.
Recently, we completed a survey of feedlots using high-moisture corn and earlage in IA, SD, ND, and NE. Results of the survey indicate that digestibility of high-moisture corn increases as material remains in the bunker but moisture content increases. This implies that nutritionists and feeders must be diligent in intake management as days in the bunker increase, particularly because this coincides with heat stress events. In contrast, feeders and nutritionists should expect earlage to have less digestibility as time passes. As this occurs, one might consider earlage as shifting from an energy and fiber source to a fiber source. Research data support this observation. Cattle fed earlage at dietary concentrations greater than 35% of the dry matter had similar feed conversion efficiency but rate of gain was slower.
Other considerations are in order. There are data that suggest that expenses to grow and harvest earlage may be greater and more variable than those to grow and harvest corn grain. This may be related to harvest costs as most feeders relying on earlage hire custom crews. Careful consideration of expenses associated with earlage crop should be made particularly when earlage makes up more than 35% of the diet.
Source : unl.edu