By Lucas A. Krueger
With summer forage harvests behind us and fall crop silage in full focus, evaluating dry matter loss from harvested forages is never more important. From a practical standpoint, dry matter loss equates to wasted fuel consumption; seed, fertilizer, herbicide, and pesticide use; and acreage.
Dry matter loss also is a true loss of feed value. This is especially true when extensive aerobic respiration occurs in loosely packed silos.
We commonly write off dry matter loss as an unavoidable outcome of crop ensiling. There is some backing to this perspective, but perhaps not to the degree that is commonly assumed.
It has long been known that the harvested plant material itself is actively respiring, so a small amount of loss is unavoidable even while silage is being transported from the field to the silo (approximately 1 to 2 percent). Once packed and sealed into the silo, however, dry matter loss is largely dictated by the metabolism of silage microorganisms and their fermentation products.
When silage microorganisms produce lactic acid, dry matter is highly conserved with little loss. Yet, competing organisms (and even some silage inoculants) produce fermentation products such as acetic acid, ethanol, ammonia, and a vast array of over 30 known volatile organic compounds. Not only do these compounds vaporize directly from silage as volatile dry matter loss, but even the very nature of their production (the conversion of sugars to volatile organic compounds) results in metabolic (energy) losses.
Lastly, aerobic respiration of silage microorganisms is a major contributor to dry matter loss. That includes long after silage has been packed. This occurs as gases, including oxygen and carbon dioxide, continue to diffuse through packed silage. This is why packing density is so vital. Respiring organisms completely consume sugars and convert them to gaseous losses, so their impact in this area is very high. Sealing silage with an oxygen barrier cover can reduce this loss. However, ultimately, it is the inhibition of respiring microbes (e.g. yeasts, molds) through strong silage fermentation that neutralizes active respiration. Silo-King® is formulated specifically with antioxidants and other ingredients to prevent loss from respiration.
To show decreased loss with Silo-King® application, a laboratory-scale silo experiment was established with second-crop alfalfa haylage. Fresh silage was either untreated (control) or treated with Silo-King® at a rate of 0.5 lbs. per ton. It was packed into silos with a hydraulic press to simulate farm-scale silo density. Each silo was constructed of PVC and sealed with a one-way gas check valve. Silos held approximately 4.5 lbs. of haylage each and were replicated 10 times per treatment. Haylage was ensiled for 50 days.
The aim of the test was to not only demonstrate lower dry matter loss in total, but to account for the fermentation products of silage. To do this, volatile-corrected dry matter loss (vcDML) was estimated using an industry-standard equation coupled with direct measures of organic acids, ethanol, and ammonia in 50-day ensiled haylage. By using Silo-King®, we aimed to direct silage microbial metabolism away from wasteful respiration and toward the beneficial recycling of silage dry matter during fermentation.
The results of this test showed Silo-King® helped reduce dry matter loss in the PVC silos from 5.9% in control haylage to 1.9% in Silo-King® treated haylage (Figure 1). This dramatic decrease is only possible by shifting microbial metabolism away from the production of wasteful fermentation products and toward highly-efficient fermentation and recycling pathways. Analysis of vcDML (Figure 2) confirmed this assessment, where volatile-corrected losses were 2.2% for control and -1.5% (a net gain) for Silo-King®.
This is by no means the first experiment to document lower losses with Silo-King®. In fact, over 30 documented, controlled studies show Silo-King® decreases dry matter loss, reduces heating, and improves forage digestibility. These studies have been used to support the registration and authorization of Silo-King® as an international forage additive used throughout Europe, Canada, Israel, South Korea, and other countries.
Silo-King® microorganisms promote highly-efficient fermentation and recycling pathways that keep silage nutrients in the silo and not the atmosphere. In untreated silage, even with good packing density and oxygen barrier covers, inefficient fermentation pathways are primed to go forward. These are key drivers of dry matter loss. Ensiling forages with Silo-King® helps protect against wasteful metabolic pathways and promotes nutrient capture in the silage. AK
To learn more about Silo-King or to order, either contact us or find an Agri-King sales representative near you.
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