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"Poisonous" does not mean deadly. Some manifestations of toxicity are subtle. The dose, as always, determines if a plant is safe source of nutrients or a toxic hazard.

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BRIEF: What do you know about formic acid and fallow?

I know you have taken an interest in the diets of deer, and thus hold you out as my only hope! (what an honor!) Anyway, what I am looking for is any information that you might be able to get your hands on in regards to formic acid for treating bale-age. I asked on deermail, how individuals were using baylage/haylage to feed deer. Only one whitetail farmer (from the Netherlands) answered. He feeds haylage treated with preservative formic acid to his whitetail and has been very successful. We would like to feed baylage to fallow, but the bales we bought this year were untreated. The goat farmers (the majority of our cash cropper's business) can't use any preservative (from my understanding it kills the goats). So our contractor used no preservatives. However, this allowed mold growth, which killed our deer! The bales that did not mold were loved, and the deer ate every bit. As whitetails and fallow are about as different as night and day, what do you know about formic acid and fallow? As this would be a higher nutritional value, we would like to go with baylage over hay, but can't figure out the technical parts to getting it right? Any ideas, or sources of information? Would you be able to get anything from Texas A&M or Penn State? Both seem to do a lot more with deer, than Cornell.I'll take whatever information I can get- even if it's a contact name and number.


Propionic acid is used in the United States to help preserve hay and haylage. It is more effective than formic acid and is not toxic to any ruminants at the concentrations applied (after all, propionic acid is an important product of rumen fermentation of feedstuff in the animal anyway). The other, more important protection against spoiled haylage is to maintain the integrity of the bag until feeding. Putting the haylage up at the proper moisture content is a factor as well. I am not familiar with formic acid toxicity in deer or goats, but since it is not used much here, I guess it won't come up any time soon. Formic acid (and formaldehyde) are catabolites found in methanol poisoning cases and urine formic acid can be used as an indication that a methanol (wood alcohol poisoning has occurred.