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Why invest in forage inoculants and preservatives?

Ben Jensen and Jon Pretz for Progressive Forage Published on 01 June 2020

We all know feeding cows high-quality forage can translate to increased profitability, thanks to its superior digestibility and encouragement of dry matter intake (DMI).

However, over the past few years, prices have been on the rise as the result of a limited forage supply. Despite its high cost, whether we are feeding on our farms or shipping down the road as a source of income, we can all agree: Forage quality matters.

Forage is a valuable farm feed ingredient – so why doesn’t forage quality get more attention? Many of us have invested large amounts of money into both equipment and seed and have dedicated countless hours to planting, cutting and checking fields. At the end of the day, many resources are dedicated to putting up quality feed, but we tend to deprioritize it once it’s back on the farm.

Quality matters

Forage accounts for more than 50% of most dairy rations. As such, the quality of the forages fed is a key determinant of profitability. High-quality silages improve balanced rations but cannot necessarily be matched with complementary feedstuffs, which often add expense. Spoiled silages make it difficult for dairies to reach their profitability goals and can lead to serious herd health and fertility issues. Furthermore, forages are our primary feed resource, and the use of high-quality silages gives us the opportunity to reduce our purchased feed costs.

When evaluating the process of producing high-quality forages on-farm, the topic of inoculants and preservatives often comes up. We are asked countless questions about the costs and application of these products and which ones might best fit a producer’s needs but, in most cases, the most important question is: Are they worth it?

Inoculants and preservatives are very different. An inoculant’s goal is to add good, viable bacteria to help direct fermentation toward a low pH as quickly as possible, and/or to improve aerobic and feedout stability by preventing dry matter loss. Alternately, preservatives let naturally occurring bacteria drive fermentation and provide the best environment possible for doing so by either eliminating oxygen or by preventing detrimental bugs from growing. The different inoculants and preservatives available on the market can vary greatly depending on their specific bacterial strains or fermentation-enhancing ingredients.

Forage crops harvested for silage contain a natural population of “good” microorganisms, which can promote the desired fermentation, as well as “bad” microorganisms – such as harmful yeasts, molds and other bacteria – that can cause poor fermentation and lead to excessive losses of dry matter, energy and nutrients. Because all silages are different, it is best to consider your unique situation when selecting the appropriate product to ensure that the “good” microorganisms win the fermentation battle and meet your goals.

When determining which inoculant to use, consider the following questions:

  1. Do you ever get smelly, butyric silage? Are you worried about dry matter losses and the loss of digestible nutrients in ensiling?

  2. Is it important to maximize feed quality (digestibility) during ensiling?

  3. Do you ever see your silage or TMR heat?

  4. Have you seen any mold spoilage in the silage?

  5. Do you have plans to move the silage?

  6. Do you plan to feed silage during warm weather?

If you answered yes to any of the above questions, utilizing a research-proven inoculant could help you manage your forage quality potential by aiding in the fermentation process, enhancing digestibility and increasing feedout stability. Our research has led us to focus on bacterial strain combinations of either Pediococcus pentosaceus and Lactobacillus plantarum or Pediococcus pentosaceus and Lactobacillus buchneri. Both of these combinations aid in maximizing fermentation while enhancing digestibility and stabilizing feedout.

When deciding whether or not a preservative is the right choice for you, consider the following questions:

1. Was the forage harvested at the correct level of maturity and at an ideal dry matter (DM) percentage?

2. Have high mold and yeast counts been a forage quality issue in the past?

3. Are you looking for a more economical approach to preserving forage? Higher-cost buchneri inoculants may not be needed if the crop is harvested at an ideal maturity and dry matter percentage.

If you answered yes to any of the above questions, a preservative may be a good fit for your forage program. Our research on preservatives has led us to focus on an enzyme- and sulfur-based product that allows unique enzymes to convert more complex forage carbohydrates to sugar.

Water-soluble carbohydrates combine with enzyme-produced sugars to result in more sugars being available for naturally occurring, lactic acid-producing bacteria. This unique combination of ingredients allows for a more rapid and efficient fermentation by the lactic acid-producing bacteria naturally present in forage, while sulfur-containing antioxidants limit the growth of undesirable yeast and molds.

Return on investment (ROI) for inoculants and preservatives

The cost of beneficial bacteria and/or preservatives is relatively low in comparison to the cost of the land, equipment, fertilizer and seed needed to start the feed-making process – and it almost always pays for itself. Thanks to increases in DM recovery, maintaining stability at feedout and improved TMR stability, we can easily expect a total ROI of around $9.70 per ton, in addition to increased profits from improved milk production when using a high-quality forage inoculant.

Improved DM recovery:

  • Expected DM recovery benefit = 4.2%

  • Assumed value of silage = $50 per ton fresh weight (30% DM)

  • Value of DM = $167 per ton = $1.67 per point of DM

  • So a 4.2% improvement is worth $7.01 per ton DM = $2.10 per ton as fed

Maintaining stability at feedout (reduced DM loss, reduced dry corn purchases)

  • 4.4% reduction in DM loss = 44 tons per 1,000 tons DM = 40.2 tons 86% DM dry corn

  • Value of dry corn = $133 per ton

  • So a value of 4.4% less DM loss at feedout = $5,346 per 1,000 tons silage DM (3,333 tons as fed)

  • At 30% DM, value per ton of silage = $5,346 / 3,333 = $1.60 per ton

Improved TMR stability

High-quality inoculants can have greater stability than 5 to 10 pounds of bunk stabilizers per ton as fed.

  • Generic bunk stabilizer price = $1.20 per pound; cost per ton TMR as fed = $6 to $12

  • So savings per ton of silage = $6 to $12 per ton as fed (assume $6)

  • Total ROI = $9.60 per ton

The inoculant business has many suppliers, and with it comes a wide range of prices for their products. They all claim to do the same thing, so it would seem pricing should not be measurably different. With a large number of options available, picking out a valuable product can be challenging.

Start by asking questions about the company’s quality control and manufacturing to verify it is a consistent product packaged to protect its viability. Also ask them about the research they’ve conducted and where it was done. Independent, third-party studies provide confidence that someone with an unbiased opinion has had positive results. Checking the application rate (CFUs per gram) is also important and should be a minimum of 100,000 colony-forming units (CFUs) per gram.

Different types of bacteria, such as Lactobacillus buchneri, can influence pricing significantly, increasing the cost of the inoculant, as it is more expensive to produce. Last but not least, support from the company can bring value through forage testing and problem-solving. “Getting what you paid for” is an old saying that certainly stands true with inoculants – and although they seem very similar, they are not the same.

It’s important to remember: High-quality inoculants and preservatives cannot make up for poor crop management or poor-quality harvest due to less-than-desirable growing and harvesting conditions. When harvesting forage, the primary goals should always focus on targeting the appropriate stage of maturity and moisture content, while managing the harvest, storage and feedout process. Optimizing forage quality at harvest allows inoculants and preservatives to capitalize on their duties, translating to increased profitability and efficiency for the producer.  end mark

Jon Pretz, Ph.D., is a dairy nutritionist with Hubbard Feeds. Email Jon Pretz

Ben Jensen
  • Ben Jensen

  • Silage Treatment Specialist
  • Hubbard Feeds
  • Email Ben Jensen