3 Best Tips for Packing Silage Piles

<< See the full story, “Silage Chopping, Packing and Storage: Top of the Heap”

Like some machine-driven line dance, it’s all so carefully choreographed. All day and into the night, multiple trucks bring finely chopped silage fresh from the field, swing around in reverse, and drop their haul at the foot of a burgeoning pile. As one pulls away, another twirls around, backs up and pulls in, just like it were cutting in.

Marvin Davis and Butch Gist

Meanwhile, the tractor—an articulated, 4-wheel drive behemoth—pushes the fodder up the slope, some 16 tons at a time. Surprisingly graceful for a 500-HP, 65,000-pound machine, it motors uphill, running right along the edge of the pile, then back, swiveling at the articulation pin, as if it had hips.

Back and forth, up and down. Watching the interchange between these machines, you can almost hear the caller: “One pulls up, the other backs in, take that load and push it again.”

Speed is key—the sooner the silage can be placed and covered, the higher its feed quality over the next year. Another key element is how densely the silage is compacted in the pile. The tractor must have some serious mass, the power to push, and the durability to withstand the constant turning and shifting between forward and reverse.

“If we don’t pack that tight and quickly we’re going to have spoilage and that spoilage is wasted feed,” says Butch Gist one of the two “choreographers,” here at the Pacheco Dairy in Tulare County, California. Gist and business partner Marvin Davis own D&G Chopping, which, as the name suggests, chops the forage. They also pack and deliver it for several large dairies in the area.

“We like to go back and really look at our piles,” says Gist of the silage, once the dairies are digging into them. “That that tells us whether we did our job right or what we need to correct. So that becomes our barometers to go back and look at the final product at feeding time.”

“It represents everything, the packing at the pile with the right equipment, and everything working just right to get the pack in right,” adds Davis. “That’s the most crucial part of our whole job.

“We’re only here for 10 to 20 days out of the year for this certain dairyman. He has to look at our product the rest of the year to see what kind of job we did. It’s kind of like we’re married to our dairymen,” Davis says with a smile. “We’ve been with some of them for 25 years. We do what’s right by them.”

What’s right when it comes to packing silage, comes down to three basic tips as provided by Davis, and University of California Cooperative Extension (UCCE) Farm Advisor, Jennifer Heguy and UCCE Specialist, Noelia Silva-del-Rio. While most of these tips apply specifically to corn silage in piles, much of the information listed below can also work for bunks, as well as packing grass and alfalfa.

1. Scheduling a Harvest Date

Says Silva-del-Rio, “Deciding on a harvest date to achieve optimal yield and quality is one of the most challenging management decisions of corn silage production.” She notes several challenges to deciding on the best time for harvest:

Varying Dry Matter (DM): Silage from multiple fields, which can vary in DM, are often mixed in a single pile. Even silage from the same field can vary in DM. For best results, she says to actually test DM. Davis’ target is 32%-33% DM.

• There are several methods for determining dry matter percentages. One for corn can be found in Heguy and Noelia Silva-del-Río’s study, “Corn Silage: What Are the Key Harvest Practices for Reducing Losses?”

Irrigation schedules: “It may take 10 to 20 days before the harvesting equipment can enter the field after the last irrigation,” explains Silva-del-Rio.

Multiple players: Farmers may be employing custom harvesters, trucking companies and packers, all working separately as well as for other farmers, potentially with conflicting schedules. It’s critical to establish communication well in advance.

To best coordinate among silage team members and set a schedule (as best as anyone can, given the unpredictable nature of, well, nature), Silva-del-Rio suggests the following:

• Share pre-harvest DM results with the silage team
• Estimate harvest duration

2. Achieving a Desirable Silage Density

Length: Davis emphasizes that “the silage is cut clean, not ragged,” explaining that to do so the harvester needs to by keeping knives sharp on harvesters. Also, he says that corn be cut at about ½- to ¾-inch. Those harvesting grass and alfalfa typically shoot for a length of 3/8- to ½-inch.

According to Davis, it’s a fine line between too short and too long. Shorter, cleaner cuts, he says, “help improve the density of the silage pile.” Yet, if it’s too short, effective fiber can be diminished. Heguy says, “It is imperative to discuss harvest parameters with the dairy nutritionist to ensure adequate particle length is achieved.”

Delivery v. Packing: Take care that the delivery of silage matches the packing speed of the tractor(s). Silage delivered too fast may cause the packing tractor operator to play “catch up” and take short cuts, thereby preventing optimal packing densities from being reached.

Layer thickness: Spread forage in layers of six inches or less to maximize compaction potential.

Top v. Bottom: Focus more packing effort at the top half of silage structures. However, Davis also offers a tip learned from 25 years in the business: In between loads, he says, frequent pushes from the outside of the silage pile help increase density and a more uniform shape that’s easier to cover.

Dryer v. Wet: Again, packers need to aim for the sweet spot. Wetter forages will have a decreased porosity and higher wet density of greater pressures generated with the added moisture in the silage pile. However, corn silage harvested too wet will have lower starch content and greater seepage losses.

Tractor Weight: There are a number of formulas available online to determine how best to use the weight of the tractor you have, but, in basic terms, the heavier the tractor the better. Also, understand that speed is plus (for more on this topic see below), so the tractors that are fast (and safe) going both forward AND reverse, as well as durable, are a huge plus.

3. Covering Silage

Quickly: According to Heguy, “The single most critical factor affecting the efficiency of forage preservation is the rapid removal of entrapped air within the forage mass, followed by timely covering of the material.”

Davis suggests the pile be covered with an oxygen barrier, such as plastic, no more than 24 hours after the building of the pile began.

Says Heguy: “Air can infiltrate the top, sides and face of poorly packed silage structures resulting in important DM and nutrient losses. Nevertheless, aerobic spoilage can be minimized if the forage is well compacted and the silage structure is sealed without delay.”

Securely: Lastly, Davis emphasizes, the plastic should be weighted—for instance, with tires—to keep the covering in place.