Making the Case for Bagged Silage ’s Impact on Herd Health

Making the Case for Bagged Silage ’s Impact on Herd Health

When making the case for bagged silage versus other storage methods such as silos, pits, or bunkers, it is helpful to start with the fundamental premise: properly stored and well-preserved silage retains more nutrients while reducing yeast, mold, and mycotoxins that can cause digestive disorders, milk production losses, reduced immunity, and poor breed-back performance. Fresher, more palatable feed also encourages more consistent, higher levels of dry matter intake, which increases digestibility, promotes weight gain, enhances milk yield, and contributes to improved reproductive performance. Collectively, these advantages translate into stronger immune function, fewer health issues, and more productive, resilient animals. These benefits are well supported by a substantial body of research, with numerous studies demonstrating clear links between feed quality, animal health, and overall productivity. “As a home-grown food source, silage is a cost-effective, sustainable way to provide dairy cattle with many of the nutrients and calories they need to stay healthy and productive,” says Mike Martin, a dairy consultant with Homestead Nutrition, Inc. in southeastern Pennsylvania.

The question, then, becomes how to achieve the highest-quality silage, and this is where bagged silage makes a particularly strong case. When forage is harvested at the proper moisture level and the bag is filled, packed, and sealed correctly, it creates and maintains an anaerobic environment. This supports efficient lactic acid fermentation and a rapid drop in pH, helping preserve nutrients while inhibiting spoilage. By limiting oxygen infiltration during storage and maintaining a relatively small feed-out face, bagged silage further helps preserve this stable environment and reduce the conditions that contribute to spoilage. In other words, bagged silage is not simply another place to store forage. It is a storage approach designed around the very conditions required to protect feed quality, preserve more of the crop’s nutritional value, keep feed fresher and more palatable, and help animals maintain stronger intake, immunity, productivity, and reproductive performance.

Proper Storage = Less Mold and Mycotoxins

According to Martin, the dairies in his area typically feed corn silage along with rye, triticale, and alfalfa haylage. Many of the smaller dairies, especially those with herds under 100 cows, store silage in upright silos or bags – or a combination of both – while larger operations are more likely to rely on piles and bunkers. One of the main obstacles in producing silage using conventional methods like piles, pits, and bunkers is the considerable risk of spoilage and loss, which can amount to as much as 30%. The problem with these conventional silage storage methods is excessive exposure to oxygen, which leads to rapid silage deterioration. The standard practice is to leave the open face of the pile, pit or bunker open for feeding, which leaves hundreds of square feet exposed and deteriorating. “There tends to be problems with some mold on the top layer of a bunker, but a well packed bag has very little if made right,” says Martin. Because oxygen exposure is one of the primary drivers of spoilage, preserving silage quality depends on properly packing forage crops to create and maintain airtight storage conditions. Among silage bagging equipment, packing is approached in various ways. Ideally, the equipment firmly packs the bag without over-stretching it while gradually moving the machine forward as the bag fills. Martin says he has seen clear differences in packing quality at dairies and poorly packed bags are not uncommon. In one case involving a Versa bagger, he said he was struck by how tightly the silage had been packed.

Astoria, OR-based Versa Corporation, a global leader in agricultural silage bagging and handling, created innovative adjustable density systems that facilitate tighter packing of longer silage bags than the industry norm, which minimizes air pockets and spoilage while maximizing storage capacity. The dairy producer told him the skid loader acted like it was “digging into a concrete wall,” which Martin took as a sign that the packing was as it should be. “The better you have the material packed, the less oxygen it is exposed to, and that is the name of the game with fermented feeds,” says Martin. He explains that oxygen allows mold to develop, and mold can lead to mycotoxins that negatively impact herd performance. This includes issues in milk production and reproduction, including cows that do not breed back as they should.

In a dairy operation, breed-back intervals are critical to maintaining consistent milk production and profitability. Ideally, cows should be pregnant again within 60 days after going dry so they can return to lactation on schedule. Modern herd management software tracks these intervals, and many dairies report an average breed-back of approximately 85 days. While they aim to shorten this timeframe, challenges like poor nutrition or herd health issues can extend it as much as 90 to 120 days, which is a major financial loss. Research further suggests bagged feed also improves overall conception rates. In a June 21, 2019, article in Farmer’s Weekly, a South African farmer stated that after switching to bagging, not only did his cows breed back faster, but his overall birth success rates improved. This means that in addition to cows getting pregnant sooner, a higher percentage of pregnancies resulted in successful births, further increasing herd productivity and profitability.

Less Yeast and Mold = More Retained Nutrients

Suppressing yeast and mold growth provides another important benefit. By limiting exposure to oxygen, the bagging process helps prevent contaminants from consuming valuable carbohydrates and proteins, resulting in greater nutrient density. “Minimizing yeast and mold allows us to preserve more nutrients in the silage. The feed is more nutritious because we are not losing nutrients to those spoilage microorganisms,” says Dr. Keith A. Bryan, who holds a PhD in Animal Science and is Technical Service Manager Silage and Dairy, North America, for global biosolutions company Novonesis. Higher nutrient density can help reduce costs by lowering the amount of supplementary feed needed to support the same level of milk production. When silage quality is poor, producers may need to provide additional concentrate to make up for the lower feeding value of the forage.

DMD, or dry matter digestibility, is a practical indicator of silage feeding value and usable nutrient density. The higher the digestibility, the more usable energy and feeding value the cow can extract from each kilogram of silage dry matter. In Agriland’s article “How does silage quality affect milk yield and concentrate feeding?”, citing Teagasc data, Hugh Harney reported that cows on 75% DMD silage needed roughly 4kg more meal per cow per day to match the milk output achieved on 79% DMD silage.

Improved Digestibility

Studies published in journals such as the Journal of Dairy Science and Animal Feed Science and Technology consistently demonstrate that high-quality silage supports more stable rumen fermentation. This stability is associated with improved fiber digestion, more consistent dry matter intake, and a lower risk of metabolic disorders such as subacute ruminal acidosis. A correctly managed silage bag produces higher levels of lactic acid, which enhances digestibility and translates to better nutrient absorption.

Martin says Homestead Nutrition’s silage recommendations are driven largely by lab results and available inventory. However, if the silage tests well and the farm has enough of it, he said it will make up the bulk of the diet. He places particular emphasis on digestibility, especially the NDFD (Neutral Detergent Fiber Digestibility) 30-hour number. A higher 30-hour NDFD usually means the forage fiber is more available, which is generally associated with better dry matter intake and often better milk production than a lower-NDFD forage. “The more digestible that crop is, the more the cow is going to be able to eat, the more she can usually make better components and more milk on it,” says Martin.

Higher Dry Matter Intake

Fresher, more palatable feed helps drive higher dry matter intake, allowing dairy cows to consume more usable energy. The link between palatability, intake and performance is reflected in Teagasc’s work on silage digestibility. Agriland’s article goes on to summarize Teagasc’s research as showing that, “in a dairy system, the higher the DMD of the silage, the more forage the animal will intake, which will result in more milk solids produced, more milk from forage, and better rumen health.”

The position is supported by The University of Tennessee Agricultural Extension Service report Managing Intake of Lactating Dairy Cows, which states, “Lactating dairy cows must consume large quantities of dry matter (DM) to provide the nutrients needed to maintain high levels of milk production. The consequences of low dry matter intake (DMI) are lower peak milk yields, lower total milk production, excessive loss of body weight and poor reproductive performance.” These intake and performance effects have also been observed in controlled research on grass silage quality.

A 2023 study by Aimee-Louise Craig, Alan W. Gordon and Conrad P. Ferris found that improving grass silage quality increased silage intake. “The increase in silage quality with 4H resulted in an increase in silage intake, milk yield and milk protein content,” wrote Craig, Gordon and Ferris in Animals in 2023.

When cows consume higher-quality feed with greater energy density, they require less overall feed to meet their nutritional needs. This enables farmers to reduce the volume of feed they must grow or purchase, or to support a larger herd with the same feed resources. Bagged silage offers dairy producers a practical way to protect forage quality by creating the anaerobic conditions needed for efficient fermentation. Once filled, packed and sealed, silage bags rapidly limit oxygen exposure, allowing fermentation to begin promptly and helping preserve dry matter, energy value and palatability. The sealed environment also helps protect silage from weather-related challenges such as rain, surface moisture and prolonged storage, reducing spoilage risk and supporting more consistent feed quality over time. That consistency matters because properly fermented silage — marked by strong lactic acid production and a low pH — helps suppress yeast, mold and other spoilage organisms, reducing the potential for feed losses, mycotoxin exposure and associated herd health concerns.

While silage has long been stored in silos, bunkers, piles and pits, more dairy producers are looking to bagging as a way to maintain fermentation quality and protect the value of their forage investment. “If you’re not putting up proper good feed, it affects everything. It affects your bottom line. It affects your herd performance, everything,” says Martin.

For more information, call (800) 837-7288 or visit versacorporation.com.

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