Forage specialist addresses on-farm inventory losses
SEYMOUR – The already short inventories of forages on many farms and the continuing likelihood of losses in the remaining supplies during storage and feedout deserves attention, according to FormAFeed forage product line manager Troy Brown.
Based in rural Reedsville in Manitowoc County for the past three years as a representative of the Nelson family-owned company headquartered at Stewart, MN., Brown outlined his concerns at the 2020 annual meeting and educational program of the Outagamie County Forage Council. He had previously been with Cargill, Inc. for 28 years.
While acknowledging that “I'm in the additive business,” Brown stressed that his goal is to advocate the best management practices for individual farms and to share ideas that farmers can put to practical use. To illustrate his points, he shared photos from his travels around the country that showed right and wrong ways to manage forages during storage and feedout.
Typical inventory losses
Research by the Extension Service and other forage specialists typically document losses of between 8% to well above 30% from the time forages are harvested to the time they are fed, Brown pointed out. So a loss of 10% “seems normal,” he remarked.
But that percentage of loss, often referred to as shrink, is a deceivingly low number, Brown believes. He says there needs to be an accounting for the evaporation or water loss in stored feeds – usually .5 to 1.5 in Wisconsin but higher in more arid areas – along with the shrink that occurs in or around storage units and during feedout.
As a result, the total losses often hit around 20% instead, Brown suggested. Applying that level of loss significantly raises the per ton costs that were calculated at the time of harvest, he noted.
A particular concern is the high potential for loss in silage bags because of how difficult it is to keep air out and because of the loss of moisture, Brown observed. “Water hides a lot of sins.”
To a question about proper storage in upright silos, Brown suggested that an aerobic stabilizer can be a good additive. It's not the storage unit that's most important but rather how it's managed, he said.
An immediate concern is the fate of the corn silage, high moisture grain corn, and snaplage that was harvested during cold weather late in 2019 and that probably did not ferment – rise to temperatures high enough while in storage to convert the sugars to lactic acid and other volatile fatty acids, Brown stated.
Under proper conditions, the ensiled forages would rise to internal temperatures – or physiological heat – of 90 to 110F for proper fermentation and then settle back to a fairly steady temperature of about 10F degrees above the ambient temperature at the site, Brown explained.
What's concerning is what will happen with the non-fermented forages when the weather warms in the coming weeks and months, Brown said. The warming ambient temperatures are likely to stimulate warming of the feeds which have not fermented and have not had their sugars converted, he stated.
Instead of compensating for what failed to happen earlier, an upcoming warming episode would be microbial heat, which often leads to molds, yeasts, and the presence of toxics in the feed, Brown explained. The yeasts will consume the lactic acid which is essential for dairy cows to produce milk, he pointed out.
Applying the L. buchneri bacteria to forages produces the acetic acid which helps to control the growth of the yeasts but that acid is less efficient for dairy cow than lactic acid, Brown continued. L. buchneri is a fixer – a product that's not necessary if storage and management practices are proper, he added.
Limiting yeast growth will provide an indirect control on the molds and the outbreak of the toxins that affect livestock health, Brown indicated. He noted that propionic acid which is a good additive for protecting dry hay, baleage, and haylage is not likely to control molds in corn.
Keeping air out
What's crucial in all situations is to keep the air (oxygen) out of the stored forages, Brown stressed. That starts at storage and continues all the way until cattle consume the feed, he pointed out. “Air is the enemy.”
One downfall on this point that Brown often sees is inadequate packing at harvest in bunkers and on forage piles because the incoming volume is greater the packing fleet of vehicles can handle or because the packing practices are not proper. He is not as concerned with the number of pounds of dry matter packed into a cubic foot of space as with how well air is excluded from the storage unit.
What's too often overlooked is who is operating the packing vehicles, Brown emphasized. It should not be the lowest ranking person(s) in the working crew. “It's the most important part of the procedure,” he said.
Instead of relying only on the tires or tracks of the packing vehicles to get the air out of the silage as it is being stored, consider renting rollers (similar to those used for applying asphalt to roads), Brown advised. He also mentioned a forage packer (Big Foot brand name from Agromatic) which applies at least 50 psi per roller while also helping to level the forage on piles or in bunkers.
Adequate storage coverage
Brown recommends placing non-permeable 1.5 mil plastic on the sidewall of bunkers and having it drop far enough to cover a portion of the floor. “There must be contact with the feed,” he stressed. One preventive practice is to use gravel bags to keep the top plastic cover from flopping in the wind as the feedout proceeds, he stated.
During feedout, about which Brown shared numerous “train wreck” photos, realize that air can easily penetrate to as much as three feet into the face of bunkers, thereby enabling the combination of moisture, air, and food source to stimulate the growth of yeasts and molds, he advised.
Proper feedout criteria
Studies have shown the exponential growth of yeast counts during short periods of time, Brown reported. That means the risk is high when rate of removal from banker faces does not match the depth to which air can travel – not to mention what can happen when forage is removed up to 24 hours before it is fed, he pointed out.
Loose feed at the foot of the bunker is a related concern because of how quickly it can heat — up to 30 degrees in 24 hours — and stimulate the growth of yeasts, Brown warned. He cited the possibility of the loss of 40 pounds of milk production per ton of forage that has been heated and spoiled in that way.
Considering the challenges of the 2019 forage harvest, Brown said his observations on the outbreak of mycotoxins in those forage are less than could have been expected. He referred to fusarium molds as “the gator we wrestle.”
Yeasts can be transferred from growth in fields or they can originate in storage units, Brown indicated. Farmers who have a consistent problem with them should test for the source, he advised.
Brown can be reached by phone at (612) 850-8403 or by e-mail to firstname.lastname@example.org. The company's website is www.formafeed.com.