Variety of fall feeding challenges addressed at UWEX seminar
MILLHOME – Where does 2019 rank in the difficulty of growing forage feeds in Wisconsin and adjacent parts of the country?
This year's challenge on that point prompted Extension Service offices in east central counties to schedule seminars in September to offer advice to farmers, crop consultants, agronomists, nutritionists, and other interested persons. Financial support was provided by the Dairyland and Rock River testing laboratories.
Manitowoc County Extension Service dairy agent Scott Gunderson views 2019 as “the 2nd most challenging year” – one that would become “the worst if there is an early freeze” to the hundreds of thousands of acres of corn not yet ready for ensiling.
In his more than 30-year career in serving farmers in the county and beyond, Gunderson considers 1988 – with it summer of prolonged heat and drought – as having been the most challenging for obtaining forages for feeding livestock. A redeeming factor from the 1988 challenge was how “we learned to feed cows with byproduct feeds,” he stated.
'Do Some Good'
As one of the organizers of the recent seminar, Gunderson said the multiple factors that have made 2019 a very challenging cropping year prompted him and his colleagues to “not let this ugly year go by” without offering some hints to those coping with the situation. He hopes the effort would “do some good” in wake of the combination of this growing year and four to five years of low prices for the prime agricultural products in the area.
“I think this is the worst year ever,” featured speaker Troy Brown of rural Reedsville remarked. Following a 28-year career with Cargill, he has been a forage quality specialist with Form-A-Feed, a privately owned consultant firm based at Stewart, MN, for the past two years. He quipped that as a consultant it is much easier to give advice than to carry out the task at hand.
From the perspective of livestock nutritionists, Brown suggested that 30 people would have 30 different answers on what makes up an ideal ration. What's not in doubt, he emphasized, is that “good quality forages make the average nutritionist look smart.”
Forage choice factors
In addition to the primary forages of haylage, corn silage, and dry hay, there are complementary or emergency fill-in candidates such a small grains for silage, sorghum and sudan grass, and various “cocktail blends” that Brown expects to become more popular. Regarding that group, he said the result “will either be good or a train wreck. If harvested properly, they can make some outstanding forage.”
One drawback with them, when compared with alfalfa, is “a tight harvest window” for obtaining high feed quality, Brown pointed out. If in doubt on when to harvest, “take before waiting,” he advised. “Sacrifice 15 to 20 percent of tonnage for quality.”
Depending on soil conditions and forage being harvested, a six to seven day of harvest window maybe required for proper ensiling. Fermentation is a challenge if the forage is too mature, Brown continued. He cited the importance of wide windrows and leaving a bit of stubble to enhance drying and indicated the possibility of a second crop under ideal conditions after an early harvest.
It could be “a brutal battle” to achieve adequate drying late in the growing season, Brown acknowledged. He suggested the possibility of adjusting equipment to have the forage move through it more slowly and noted that some growers address the drying challenge by burning standing sorghum-sudan with glyphosate (a three to four-day withholding window).
Corn silage harvesting
Whether frozen or not, harvest corn for silage at the whole plant moisture proper for the type of storage, Brown said. For best fermentation, he recommends a chopping length of 19 millimeters for processed corn silage at 68 percent moisture compared to 10 to 12 mms for alfalfa haylage. Shorten the cut as moisture declines, he added. “Moisture hides sins.”
A new idea borrowed from Denmark and employed on a few large dairy operations in Michigan is “compact feeding – just Google it,” Brown reported. He described it as a mushy corn silage chopped at only 6-8 mm (about a quarter inch), resulting in “great fermentation,” very good storage, and minimum separation in the feed bunk.
Kernel processing scores
Brown calls for far more attention to corn silage processing scores – both in visual and tool measuring. Far too many of the silage samples sent to testing labs fall short of his ideal of having a great majority of kernels broken into four to six pieces rather than only being nicked or broken.
Doing or not doing that is going to make the difference between dairy operations which survive today's economic and management challenges and those which don't, Brown predicted. That's because of the essential role of the starch in corn kernels to boosting microbial protein concentration to support higher milk production, he explained.
Achieving much higher kernel processing scores will require increasing roll speed differential, reducing roll gap spacing is also critical as rolls age, Brown pointed out. And, “in my opinion, the future of kernel processing will be at the storage unit, not in the chopper.”
Achieving and protecting quality in storage is another crucial link in the forage chain, Brown stressed. This means getting air out at storage and keeping it out until feeding in order to prevent the growth of yeasts and molds, he said.
A good combination of moisture and packing leads to an adequate fermentation in which the sugars are converted to volatile fatty acids, of which “lactic acid is king” because of the energy it supplies in the forage, Brown indicated. Keeping the pH at 3.5 to 4 is another goal, he added.
While inoculants can be helpful for fermentation and protecting corn silage during storage, Brown believes the value of L. Buchneri inoculant “has been oversold.” In addition to being fairly expensive, he said it produces a minimally useful microbial acid. “Management should control bunker reheating,” he remarked.
Spoilage in storage
Brown reminded the attendees of the importance of controlling air when putting silages into storage, whether in piles or bags. The top three to four feet of piles and the tops of bags are in jeopardy of spoilage without proper packing, he warned.
Regarding the packing on piles, Brown shared illustrations of varying practices that he has observed. To achieve desired results, he emphasizing having layers of no more than six inches of new forage when starting a new round of packing and increasing the number of tractors rather than boosting the weights for packing.
Beyond the equipment, it's important to have very capable operators of the packing tractors, Brown stressed. He finds that the task is too often assigned to the lowest ranking people on a harvesting team.
Once the filling is completed or if there is a harvest interval, sealing the top and sides with plastic layers and making sure there is tight contact with the feed on the top is necessary, Brown sais.
Repeating his earlier concern, he suggested that the amount of spoilage (lost or very low quality feed) could be the breaking point on whether some dairy operations survive the current set of challenges.
With silage bags, there's no easy solution to having only five to seven pounds of forage per cubic foot in the top portion, Brown indicated. This means far too much air is present and the opportunity for mold and yeast growth greatly increases, he observed.
“There's no perfect type of storage,” Brown remarked. “Which gator do you want to wrestle?”
Degrees of silage heat
Of the two types of silage heat, the physiological temperature of 95 degrees or higher shortly after ensiling is the fermentation process, followed by a drop to between 5 to 15 degrees above the ambient temperature, Brown noted.
What's unacceptable is the secondary or microbial heating that is prompted by the combination of exposure to air and the presence of yeasts and molds, Brown pointed out. This also allows the pH to rise and results in massive spoilage of the feed, he warned.
Because the molds and yeasts originate in corn fields, their transfer to the storage units can be controlled, at least to a limited extent, with the application of fungicide and the incorporation of one or more inoculants, Brown observed. But he emphasized that keeping air out of the stored feed is by far the most important factor.
During feedout, organize the bunker piles so the daily removal will be 12 inches from the face rather than only six inches, Brown advised. He shared examples of improper practices and images of the thermal technology which documents internal temperatures in silage bunkers.
Citing the fatalities and injuries that have occurred when silage piles tumbled, Brown urged all parties not to overlook safety practices when working next to bunker silos.
Brown can be reached by e-mail to firstname.lastname@example.org.