Using Preservative on Alfalfa Dry Hay

It is no secret that there are many different preservatives and additives marketed for use in dry hay and some with crossover benefits when applied to haylage/baleage; there are also various modes of action for these different additives.  We aim to settle on one specific preservative to use on our alfalfa which will be packaged as dry hay and primarily marketed to the equine industry.

Why Use a Hay Preservative?

Having the ability to safely bale at a higher moisture content while preventing mold development and heating of the bales is one of the biggest advantages gained while using a preservative.  It might not necessarily be needed all of the time — but the biggest consideration for our operation is risk management.  Both risk in the sense of potential depressed revenue from hay that is degraded or lost due to spoilage, the inherent dangers of toxicity to animals during feeding lower quality hay, and of course the risk of spontaneous combustion and fire which would significantly compromise farm facilities and equipment.

Being able to bale the alfalfa hay at a higher moisture content, and know that it’s safe for storage should nearly eliminate threats incurred by volatile weather, and allow for much better leaf retention, which will increase the quality of the hay.

With the goal of producing high-quality alfalfa dry hay, our standpoint is that having a means of readily applying a preservative, and having the best-suited product available when it’s needed is going to be one of the many keys to the success of our operation.

Different Modes of Action and Types of Preservative

One of the most common preservatives we have seen mentioned is propionic acid, or another type of organic acid (such as acetic acid) which, when applied at just the right amount, acts to inhibit mold and yeast growth by decreasing the pH; applied at too high of a rate, and all microbial activity can cease.

There has been some mention of using anhydrous ammonia directly injected into the bales to essentially displace or otherwise render the oxygen inaccessible in lower quality grass hay.

And lastly, there are bacteria and enzyme-based inoculants (such as Silo-King by Agri-King) which essentially work against the other microorganisms that are present to prevent mold, and effectively increase the lactic acid-forming bacteria to promote fermentation.

We will not have first-hand real-world experience with the preservative until later this year, however, judging by the studies, reports, and general feedback we’ve gathered — it seems like using Agri-King’s Silo-King preservative fits the requirements for what we’re after.

The Special Blend of Silo-King

As an added benefit to using Silo-King, the bacteria within the product will actually provide for a quicker fermentation and the enzymes will work to increase digestibility by pre-digesting cell walls without altering the taste.

Silo-King Test Results
Published alfalfa sample results from Silo-King literature.

So, Why Not Use Acid?

Simple answer; It’s an acid.   Sure, if it is applied exactly at the right rate, and the residual is managed properly, it can likely work well and not degrade performance or the life of equipment — but at the end of the day, it’s an acid.  Dealing with damage to equipment is enough of a reason for us to not have this option at the top of the list.

Through discussions with prospective buyers, we’ve also encountered a recurring concern over buying hay that has an acid preservative applied — this is just another unnecessary obstacle to combat when marketing the hay.

TL;DR Conclusion

The choice has been made to use Silo-King on our alfalfa dry hay, and apply it using the digitally controlled Sidekick granular applicator.

Although there has been some mention that bacterial and enzyme inoculants aren’t as effective when compared to acid, we have heard many reports that it does work well in practice — and we will soon find out first-hand.