Dairy's goal: Minimum density of 15 lbs DM/cu ft
Doing a bang-up job of packing haylage going onto storage piles to maintain forage quality and prevent dry matter losses is a top-tier priority at 2,800-cow Dairy Dreams, LLC, near Casco, WI.
“We buy all of our feed, so we simply cannot afford the shrink or waste that occurs if packing isn't done right,” says Don Niles, a partner in Dairy Dreams along with John Pagel. “With today's input costs, shrink is devastating. But even under better economic conditions, we don't feel it makes any sense to give up any of the feed we're paying for.”
An often-cited Cornell University study in the 1990s showed how missing the mark on packing density leads to waste and increased operating costs. In that study, with packing density at 10 lbs of dry matter per cubic foot (DM/cu ft), dry matter loss in alfalfa haylage was just over 20% after 180 days in storage. At 15 lbs of DM/cu ft (considered a minimum acceptable density for preventing shrink), losses dropped to just under 16%, and at 22 lbs of density, they were just 10%.
In a typical year, Dairy Dreams puts up 5,000 tons of haylage in piles. First, third and fourth cuttings go onto a 160'-wide asphalt pad. A second 160'-wide pad is used for second cutting. The dairy also puts up 30,000 tons of corn silage, stored on two 200'-wide asphalt pads, annually.
The goal is to achieve a minimum density of 15 lbs of DM/cu ft when piles are packed. But that mark is consistently exceeded and densities as high as 21 lbs have been achieved. To continue meeting or exceeding their goal, Niles and Dairy Dreams operation manager Rick Havel emphasize consistency. Packing in thin layers is one focal point.
“Thicker layers just don't pack as well,” says Niles. “We have a policy of taking no more than a 6” layer up on the pile even though it seems a little slow at times. We feel that gives us a maximum packing density and maximum shrink control.”
Coordinating the amount of feed coming into the packing area with the pace of the packing tractors is a key to keeping the layers thin.
“We can't afford to slow down the custom choppers,” says Niles. “No 1, we're paying them by the hour. No. 2, we like to get them in and out as quickly as possible so they can move on to take care of other customers.
“We're not concerned if there are two or three loads of forage piled on the ground waiting to be packed as long as we're making the thin, smooth layers we want up on the pile. We certainly never want to be in the situation where we have trucks waiting to unload because there's too much feed on the ground. But we are willing to let a load sit on the ground for four or five minutes while we handle the loads ahead of it.”
While smaller particle size (shorter length) facilitates compaction, Niles is reluctant to reduce particle length by too much. “But from a cow health point of view, we need longer-stemmed forage. We just apply ourselves to packing the longer-chopped forage as best we can.”
Harvesting haylage at the proper moisture can also involve a trade-off. Wetter forage compacts more easily, but is more susceptible to butyric acid fermentation. Niles' goal is to make haylage no wetter than 38% dry matter (62% moisture).
“Sometimes we're tempted to go below that level to beat a rain,” he says. “But we try to do everything we can to avoid butyric fermentation. From the standpoint of trying to control shrink loss, it's just as devastating as surface spoilage is.”
Packing with enough iron is also emphasized at Dairy Dreams. For haylage, when just one chopper is running in the field, John Deere 8120 and 8210 tractors are each fitted with a blade, 5,000-lb concrete block mounted to the three-point hitch and solution in the tires. For corn silage, the dairy uses two tractors per chopper running in the field.
“So if we have three choppers going, we'll have six tractors up on the pile — three blade tractors and three packing tractors,” Niles explains. “Our main goal is to keep weight evenly distributed as we go across the pile.”
University of Wisconsin extension ag engineer Brian Holmes agrees that having sufficient weight on the pile during packing is an important factor in achieving adequate density. If you opt to add extra weight to a tractor (by adding a weight to its front or rear, using wheel weights, etc.) he recommends first checking with its manufacturer.
“They might have an upper weight limit,” Holmes notes. “If you exceed that and something happens to the tractor, they might not honor the warranty.”
If you opt to pack with more than one tractor to get more weight on the pile, he recommends using tractors of similar weight.
“If one is appreciably lighter than the other, it will tend to just float across the pile rather than getting any serious packing of material done. That kind of defeats the whole purpose of using an additional tractor.”
At Dairy Dreams, forages are covered as soon as packing is completed on an area large enough to hold a 60'-wide strip of tarp.
“We always double-plastic all surface areas with two layers of conventional black/white, 5-mil plastic,” says Niles. “We have experimented with some of the newer, oxygen-barrier plastic material. It seemed to work well enough. But, in my opinion, it really was no better than the two layers of plastic we've been using.”
To ensure the packing crew is meeting the targets for density, the dairy's nutritionist occasionally takes compaction samples. On a more routine basis, dairy employees also keep close tabs on surface spoilage.
“Twice a week, we'll have our fellows pull back the plastic and tires from the end of the forage pile that's going to be fed during the next half week. We'll pitch off any spoilage on top of the pile. When we do have to pitch feed, we're disappointed. If we've done our job right, feed should be of high quality to the top of the pile.”
The dairy also makes use of Feed Watch software to compare tons of feed coming into the pile with tons going out. “Using that measurement, we like to have less than 2% shrink,” says Niles.
University of Wisconsin Extension has developed a spreadsheet for calculating how changing values for tractor weight(s) used in packing, forage delivery rates to the pile, packing-layer thickness, etc., influence the final density of silage piles. To use the calculator, go to the Team Forage “Harvesting and Storage” Web page at www.uwex.edu/ces/crops/uwfor age/storage.htm. Scroll to Silage Pile Density Calculator.
For a slideshow and interview with Niles on his farm's packing techniques, visit hayand forage.com and click on Silage Slideshows.