ROLLING NOT SO DRY MIXED GRASS HAY

With that said, if moisture is above 24% or so I'd not waste the barn space on it, it will mold, it will heat, it will become nothing much more than high priced mulch; it may heat again after 6 months inside. Most of us have to make at least one crop into something that nothing will eat to learn that it is better to get it rained on or make it into silage than to roll it wet, waste the time and fuel, and have less than nothing.

Heating (and mold) is caused by the growth of mold (fungi) and bacteria. Like any other infectious disease we must have a host, a pathogen, and a favorable environment. The host being hay, pathogens are present from the soil, the only variable being the environment. When baled hay exudes stem moisture causing it t sweat (this is why the moisture content will rise over a few days). If their is moisture present (above 14.5%) bacteria and fungi begn to grow. As they reproduce they consume oxygen and give off heat. If the moisture content is below 20% this process rarely produces temps in exces of 110 deg F. IF, they run out of oxygen or water the process stops. At this point if water is present anerobic fungi begin to reproduce which give off heat up in the mid 140's. As long as oxygen is excluded at this point the hay ferments and we make silage (fungal/bacterial) populations depending on water content. If oxygen is reintroduced we begin rot. The bad part of this is normal bacterial/fungal growth stops at 125 deg F due to heat killing them. At this point heat resistant bacteria/fungi take over who give off large amounts of heat as temps approach 180 deg enzyme rxns take over which can result in temps above 190 where ignition is likely.

We typically see two spikes in temps with damp hay. Spike 1 is typically at 6 -8 days due to natural heating and fermintation. Spike 2 occurs (typically) at 6 weeks but can happen any time as moisture migrates in the bale to spots with unoxidized starches. As long as air flow is adequate we rarely see severe problems above 24%. A single bale rarely catches fire. It is when they are in a stack of rolls which traps heat. The mass of the stack allows the temps to rise to dangerous levels. Wha can also happen at the 6 month point is that the hay can be rotting from an anaerobic wet spot until it reaches oxygen, when it does is will begin respiration and temps can spike rapidly.

I had a drip in a roof in a barn with stacked rolls. Hay had been in the barn for 2 years, last winter I smelled something funny and got to looking. Rot where the two rolls touched. I removed the hay and the bottom roll on the top sde was rotted almost through, temp was 225 deg F (after 2 years). If it hadnt been so wet it would have been on fire, as soon as it rotted to the dry hay I would have had a barn fire with those temps.

Move rolls to a gravel area (outside) in a high spot and arrange rolls with enough room to walk around each one. Forget about them for a week. Take a temp and moisture reading. Check weekly until moisture content is down under 20 and temps are normal. If temp stays below 135 degrees the hay should be ok moderate to high quality (assuming it was when baled). When moisture content is below 18 inside and out and at least a month has past they should be ok to put inside. This is how I 'sweat' dry hay before storing stacked inside. Wish I had my camera back I'd send a pic. Got 88 rolls doing just this now. The gravel keeps the strings from rotting on the bottom. Then I put my bottom roll on its end inside, stack the other rolls on top in a pyramid.