The recipe for making great silage that you have been looking for

When choosing products for making silage, there is a lot to think about: what type of crop, dry matter content, storage method or when it will be fed to the cows. In the summer of 2018, many farmers experienced problems with heating in the silage stack – how could this be prevented?

Despite uncertain milk prices, it is still a good idea to use additives for silage or grain / corn preservation. When choosing your silage strategy, it is important to think about the hidden costs – such as loss of dry matter during storage. Only a few actually weigh in all the newly harvested forage when making silage, and compare it to how much is fed to the animals and therefore don’t know their actual loss in dry matter content. Research shows that it is not uncommon to have a dry matter loss of 15-25%, which means that if you harvest 100 ha, you may have losses equivalent to 15-25 ha1. After all, the costs of cutting, chopping, transporting and filling the silo are for to the entire harvest, so that loss of dry matter add up, both directly and indirectly to your bottom line. Fortunately, loss of dry matter can be reduced with the help of silage additives.

In recent years, it has become common to use biologically based silage additives in the form of hetero- or homofermentative mixtures of probiotic bacteria. However, many farmers don’t see the economic advantages of using these products. Research, both locally and internationally, seem to support these observations, and have also yielded mixed results, with little or no effect seen in both maize2,3,4,5 and grass silage4,5,6.

Outside of Denmark, in our neighboring countries, ther has been a long tradition of using chemically based silage additives in the form of organic acids. In fact, organic acids have been used for more than 50 years to prevent yeast and moulds in the silage7 – and with great evidence of success. Unfortunately, there are very few studies that directly compare the use of probiotic cultures and chemical additives to silage.

The advantage of ensiling with organic acid is an immediate pH reduction of one unit, which saves valuable sugars and energy forage. Sugars, that with bilogials, would otherwise be consumed by lactic acid bacteria to achieve a pH reduction. To achieve the fastest pH lowering, it is recommended to use products containing formic acid or the salt of formic acid. The great advantage of using formic acid and propionic acid salts like sodium formate or calcium propionate is that they have almost the same effect as the pure acids, but are much easier to handle on the farm. It also means that the products are classified as non-corrosive on metal.

Oxygen is the enemy of great silage, so it is paramount to avoid oxygen in the silage stack or silo. Many farmers are good at stacking in thin layers and packing the silage well to get rid of air. It is just as important that the stack is covered well with plastic on the sides and double layers on top, and to finish with heavy tarpaulins, sand or wood chips for weight on top. Make sure the plastic is tightly packed so that the wind does not “push” air in. Many use tires as weight – but the disadvantage is that they leave a lot of plastic without any weight or coverage. You should avoid from using straw to cover the stack. Rats and mice build nests in the straw and the risk of biting holes in the plastic is great – with oxygen leaks as a result.

How to cover the silage silo

Packing a silage silo

Tips for making silage:
• Do not fill everything in the silo in one go; it is better to ..…
• Add a 20-30 cm layer of forage and then pack it down heavy machinery
• Continue packing ½-1 hour after the last load
• Cover the silo tightly and immediately after the final load
• Adjust the package weight of the machine to at least 0.25 * load capacity per hour. For example: If the capacity is 40 tonnes per hour * 0.25 = The machine should weigh at least 10 tonnes to be packed tightly enough.
• In order to manage when the harvesting capacity is high, you can place two silos at the same time, if there isn’t enough space for both loading and packing simultaneously in one silo.

In order to ensure a good and stable silage right up until you start using it, we recommend using propionic acid or the salt of the propionic acid to keep it stable. The propionic acid inhibits yeast and mold as well as prevents heating, increasing storage stability.

Remember that a silage with a high dry matter content and sugar content, i.e. a good silage, has an increased risk of heating up due to the growth of yeast and mold when the silo is opened. During warm and humid harvesting conditions this can frequently be a problem.

If you have a problem with the generation of heat when you start using the silage, spraying propionic acid or another propionic acid-based product on the fresh cut help. We recommend preventing this by spraying ProMyr ™ XR 680, a premium blend product, for silage. It has a variety of effects and can be used as silage additive for both the grass, maize or mixed silage and provides a quick lowering of the pH, while ensuring against yeast and mold.

Note that the ProMyr ™ XR 680 is not suitable for preventing heating of TMR or complete feed. We recommend using propionic acid, or better yet ProMyr ™ TMR Flexible – or ProMyr ™ TMR Solid, if you need a dry product.

Last but not least – should you be unlucky enough to find yeast or mould at the time of feeding, you can prevent some of the negative effects of mycotoxins by using a toxin binder. Agmondo has a wide range of products for this purpose; take a look at the table below or contact us if you need guidance on which products you should use for your situation.

Dry matter % Grass silage Mixed silage <25% clover Clover silage >25% clover Corn Whole grains TMR Mixed grains <30% moisture Mixed grains >30% moisture Heating Spores
ProMyr™ XR 680 25-45 %
ProMyr TMR™ Flexible >45 %
Propionic acid
ProSid MI™ 700

↑ very well suited      → suitable       ↓ not suitable 

  1. Tab ved ensilering, opbevaring og udfodring, Charlotte Jensen, Ensilering af majs og græs Intern rapport, Husdyrbrug Nr. 21, marts 2010
  2. Virkning af ensileringsmidler i majs – ensilering 2008 Niels Bastian Kristensen et al. Ensilering af majs og græs Intern rapport, Husdyrbrug Nr. 21, marts 2010
  3. Giver ensileringsmidler i majs mere mælk i tanken og sundere køer? Karen Helle Sloth et al. Ensilering af majs og græs Intern rapport, Husdyrbrug Nr. 21, marts 2010
  4. Effects of silage additives on ensiling. Muck RE and Kung In: Silage: Field to Feedbunk. Proceedings from Silage: Field to Feedbunk North American Conference. Ithaca, New York: Northeast Regional Agricultural Engineering Service; 1997: pp. 187–199.
  5. The Effects of Various Antifungal Additives on the Fermentation and Aerobic Stability of Corn Silage Kleinschmidt et al. 2005, Dairy Sci. 88:2130–2139
  6. Virkning af ensileringsmidler i græs – ensilering 2009 Niels Bastian Kristensen et al. Ensilering af majs og græs Intern rapport, Husdyrbrug Nr. 21, marts 2010
  7. Silage review: Factors affecting dry matter and quality losses in silages Borreani et al. 2017, Dairy Sci. 101:3952–3979

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