High Moisture Corn (HMC) Management By: Jeremy Martin, Ph.D., Great Great Plains Plains Livestock By: Jeremy Martin, Ph.D., Livestock Consulting Consulting AsAs harvest approaches and cattle feeding margins remain harvest approaches and cattle feeding margins remain negative, take the opportunity this harvest to get the mostthe negative, take the opportunity this harvest to get outmost of your corn crop. putting HMCupisHMC part ofisyour out of your cornIfcrop. If up putting part of your repertoire, I amtogoing to challenge you tothe manage repertoire, I am going challenge you to manage entire the entire process in order to achieve success. From an process in order to achieve success. From an agronomic agronomicHMC standpoint, expands the harvest seasoninstandpoint, expandsHMC the harvest season and reduces andgrain reduces grain lossa by 3-6%.standpoint, From a feeding field lossin-field by 3-6%. From feeding HMC standpoint, HMC improves both gain and conversion improves both gain and conversion while typically resulting typically less the shrink thanofdry corn. in while less shrink than resulting dry corn. in While benefits HMC are While the benefits of HMC are apparent for both farming apparent for both farming and feeding operations, success is feeding operations, success is in the details. in and the details. Most importantly, HMC be stored at the right Most importantly, HMC mustmust be stored at the right moisture moisture level tocattle maximize cattle performance. The ideal level to maximize performance. The ideal moisture moisture range for harvesting HMC is 28-32% moisture, range for harvesting HMC is 28-32% moisture, with with maximum energy and density cattle performance maximum energy density cattleand performance between between 30-31% moisture. Once the kernellayer, reaches 30-31% moisture. Once the kernel reaches black black layer, HMC harvest can and should begin in HMC harvest can and should begin in order to realize order the to realize the most value. Timing is critical because by most value. Timing is critical because by the time corn dries the time corn dries down to 23% moisture, it will feed down 23% moisture, it will feed as with the same withtoessentially the same energy dryessentially corn, but average energy as dry corn, but average energy value increases energy value increases approximately 0.3% per point of approximately 0.3% per point31%. of moisture betweencorn 23 and moisture between 23 and Additionally, that 31%. Additionally, corn that is stored above 30% moisture is stored above 30% moisture becomes more digestible becomes more digestibletoover compared corn stored over time compared corntime stored at 24%tomoisture or at less. 24% moisture or less. summary, ideal HMCstart harvest In summary, idealInHMC harvest should once should black layer and blackstart layeronce is achieved and is beachieved completed bybe thecompleted time corn byhas thedried time corn has dried down to 28% moisture, down to 28% moisture, resulting in anresulting average in moisture an average the pile of 30-31%. in moisture the pile ofin30-31%. Almost every year, some corn is going to get for Almost every year, some corn is going to harvested get harvested HMC below below 26% moisture. When you expect to that for HMC 26% moisture. When youthat expect happen, your your process should be adjusted to gain value to happen, process should be adjusted to more gain more outvalue of theout drier Ourcorn. recommendation is to begin is to of corn. the drier Our recommendation beginwater adding water corndrops moisture below adding when cornwhen moisture belowdrops 27%, and 27%,onand focus on adding enough volume to back bringtothe focus adding enough volume to bring the corn corn back to In 30% moisture. corn 30% moisture. order to allowIn theorder corn to to allow take inthe more to take in more moisture, it may be necessary to reduce moisture, it may be necessary to reduce the particle size of particle sizecorn of the grind. corn drops below thethe grind. When drops belowWhen 23-24% moisture it is 23-24% moisture is very to difficult in most very difficult in mostitsystems reconstitute the systems corn to to reconstitute to 30% anda therefore we 30% moisture,the andcorn therefore wemoisture, recommend cutoff of 24% recommend a cutoff moisture for corn that is to moisture for corn that isofto24% be ensiled. be ensiled. Particle size is the next critical point of HMC management. Particle size is the next of dependent, HMC management. The correct particle size critical is very point feedlot and is The correct particle size is very feedlot dependent, and influenced by infrastructure, bunk management, and other is influenced by infrastructure, bunk management, and available feedstuffs. Infrastructure is important, as it can other available feedstuffs. Infrastructure is important, limit the amount of HMC a feedlot can process in the ideal as it canwindow, limit theand amount of the HMC a feedlot can process moisture because type of equipment in the ideal moisture window, and because the type of present determines the best way to process corn. The ideal equipment present determines the best way to process particle an operation willatstrike a balancewill between corn. size The at ideal particle size an operation strike a harvest efficiency, energy density, and the risk of digestive balance between harvest efficiency, energy density, and disturbances. the risk of digestive disturbances. 22
Feedlots grinder) Feedlotsthat thatgrind grindHMC HMCwith with aa hammer mill (tub grinder) generally grindgrind that packs tighter,tighter, but ferments generallycreate createa finer a finer that packs but more quickly in the rumen in resulting greater risk ferments more quickly in resulting the rumen in of greater risk of acidosis andDry bloat. Dryconversion matter conversion cattle acidosis and bloat. matter of cattleoffed fed hammer-milled is usually than those fed hammer-milled HMCHMC is usually betterbetter than those fed rollerroller-milled HMC but dryintake matter andusually gain are milled HMC but dry matter andintake gain are usuallyMonitoring lower. Monitoring particle size is important, lower. particle size is important, with an with an achievable being no more than 3-4% whole kernels achievable goalgoal being no more than 3-4% whole kernels and and not more than 20% fines (<1mm). Commercially not more than 20% fines (<1mm). Commercially available available sieve shakers well for determining particle sieve shakers work well work for determining particle size size distribution, and should be used at least twice distribution, and should be used at least twice dailydaily to to determine if adjustments are needed. determine if adjustments are needed. Roller-milledHMC HMCcreates creates less fines, which results in Roller-milled less fines, which results in lower lower risk of digestive deads along with increased dry risk of digestive deads along with increased dry matter matterand intake and gain compared with hammer-milled intake gain compared with hammer-milled corn. On the corn. On the other hand, less fines means other hand, less fines means roller-milled cornroller-milled is more corn is more pack. Some offer manufacturers challenging to challenging pack. Sometomanufacturers roller mills offer roller mills with differential drives on at least one set with differential drives on at least one set of rolls orderinto of rolls in order to create enough fine particles toin assist create enough fine to assist in apacking HMC. If packing HMC. If particles milling HMC with roller mill, strive milling HMC with a roller mill, strive for essentially no for essentially no whole kernels and you should still be whole and (<1mm) you should still10%. be able keep fines able tokernels keep fines under In to a perfect world, (<1mm) under 10%. In a perfect world, each kernelpieces. would each kernel would be split into 6 roughly equal be split into 6 roughly equal pieces. However, corn However, corn processed in such a manner does take processed a manner take more time to pack,toso more timeintosuch pack, so theredoes is a time-saving advantage there is a time-saving creating more fines. advantage to creating more fines. After Aftermoisture moistureand andprocessing, processing,correctly correctlypacking packingHMC HMCisis next on the list. In general, adequate packing requires a a next on the list. In general, adequate packing requires pack tractor for each 4-5,000 bushels per hour of grinding pack tractor for each 4-5,000 bushels per hour of grinding capacity. tractors should not not be sitting between loads, capacity. Pack Pack tractors should be sitting between but constantly on the move. a fallacy pushing loads, but constantly on the There move.isThere is a that fallacy that corn up iscorn enough during the during day if you wellpack at theit pushing up is enough the pack day ifityou wellofatthe theday. end of thetruth day.is, The truth only the uppermost end The only theis,uppermost 6 inches of 6 inches the pile so each load corn in the of pilecorn getsinpacked, so gets each packed, load should be packed be in. packed as it comesHMC in. A well-packed HMCat asshould it comes A well-packed bunker will contain bunker will at least 45 lb foot. of dryOnce matter per cubic least 45 lb of contain dry matter per cubic packed, HMC foot. Once packed, HMC should be covered immediately should be covered immediately after completion of the pile completion of the pile to achieve the highest quality. toafter achieve the highest quality. Anotherconsideration consideration HMC production includes Another forfor HMC production includes inoculants,which whichis aisdecision a decision you should make in inoculants, you should make in conjunction with your nutritionist, based on the conjunction with your nutritionist, based on the costcost of of inoculation relative to the value of corn – and your ability inoculation relative to the value of corn – and your ability to to correctly apply inoculant. to feed at least correctly apply inoculant. AlsoAlso try totryfeed at least 6” off6”the off the face of the pile daily and maintain a vertical, flat face of the pile daily and maintain a vertical, flat face with face with no loose corn at the base of the pile to minimize no loose corn at the base of the pile to minimize shrink shrinkfeedout. during feedout. during With some planning and quality control, and some help With planning and some volume help from fromsome Mother Nature,and youquality can putcontrol, up a tremendous Mother Nature, you can put up a tremendous volume of of HMC in a short period of time. Because the process HMC in a short period of time. Because the process needs needs to occur quickly, it is tempting to rush through toprocessing occur quickly, it isfocus tempting to rush through processing and not on quality. This year, take the and not focus on quality. This year, take the time to manage time to manage the process for a short period of time so the process for a short period of time so you can enjoy the you can enjoy the results throughout the rest of the year.** results throughout the rest of the year.** 22
