From the moment you plant your carefully selected seed for silage, every step you take to manage the crop impacts its potential nutritional value. Steps taken during harvest and processing significantly affect overall silage quality and feed value. Below are some factors that can help you maximize the nutritional value of your silage.

Dann Bolinger

Length of chop and kernel processing

Length of chop is getting closer scrutiny these days as a way to leverage the crop’s nutrient feeding potential. Shredding or tearing the corn plant as it is chopped has allowed farmers to experiment by cutting 1-inch to 1.5-inch lengths, rather than conventional 0.75-inch lengths. New processor designs are also creating a higher differential between the rolls and improving kernel damage, making starch more available to cows.

It is important to carefully monitor chop length and kernel processing to determine silage consistency and quality. That said, before deciding to change your chop length or kernel-processing practices, you should take into consideration all of your crop conditions, including whole plant dry matter, kernel dry matter and storage practices.

Silage shrink

Silage shrink is one main way producers lose nutritional value of their silage, often forcing growers to feed their livestock additional grain to make up for the loss. Shrink can occur in many ways: mechanical, wind, fermentation, leachate, aerobic instability at feedout, mixing errors, scale inaccuracy, feedout surface management and direct spoilage.

Shrink begins with plant cell respiration and aerobic microflora utilizing sugars to produce water, heat and carbon dioxide. The escaping gaseous carbon dioxide and metabolically generated water reflects dry matter loss from the silage. These processes continue until the oxygen in the silage mass is depleted. Shrink consumes the most valuable, digestible silage nutrients, which then must be replaced with an equal energy source.

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Efficient fermentation is one factor that can reduce costly shrink. The goal of silage fermentation is to drop the pH as fast and efficiently as possible to a stable range below 4. Corn silage is notorious for possessing high levels of yeast. While silage is in the anaerobic state, yeast is not typically an issue – but when reexposed to oxygen, yeast multiplies quickly and can initiate heating and silage deterioration, reducing both quality and palatability.

Packing the silage at the time of harvest helps force the air out of the feed pile and accelerates anaerobic conditions and fermentation. The standard rule for calculating tractor weight for good packing is to multiply the tons of feed harvested per hour by 800.

If feed is being added to the pile faster than it can be leveled and packed, more tractor weight is needed to avoid reductions in silage density. Shape piles and fill bunkers so you can drive over every inch of the bunker without your tires sinking more than 3 to 4 inches before the next layer of silage is added. If the pile’s slope causes the tires to slip to gain traction, the pile is too steep. Not only is this a safety hazard, but it may cause more feed loss because of poor compaction.

Reducing losses at feedout

A pressing problem today is managing shrink on the wide, exposed silage faces common to large bunkers and piles. These exposures can lead to dangerous levels of microbial heating. Common management causes of microbial heating include: when the silage face is left open for an extended period of time, when uneven or jagged cuts exist on the silage face and when the silage has been poorly packed. To reduce heating on an open bunker or pile, use a facer. Doing so ensures a clean edge and minimal disruption to compaction. Also, feed out across the entire bunker, evenly removing a minimum of 6 inches daily.

Tools you can use to measure silage heating include infrared thermal imaging cameras, compost thermometers and digital thermometers. If silage begins heating beyond 10 to 20°F above the ambient temperature at which it was harvested, it could signal challenges ahead.

Use of inoculants

The proper application of a research-proven inoculant will help preserve your investment in seed genetics. A proven Lactobacillus plantarum inoculant speeds up and increases the efficiency of the fermentation on the front end; this is a vital step to reduce shrink plus unwanted bacterial and yeast growth.

Use an inoculant with Lactobacillus buchneri to reduce heating and dry matter losses at feedout. Some inoculants, using a novel Lactobacillus buchneri strain, also help improve fiber digestibility. These inoculants reduce the need for supplemental energy and protein sources in the ration and can dramatically improve the value of feed. PD

Dann Bolinger

PHOTO: One opportunity for silage nutritional loss is at feedout when the silage face is exposed for an extended period of time. Remove a minimum of 6 inches daily to reduce loss. Photo by Lynn Jaynes.