Grazing in Michiana
As you drive around the countryside, you can see multiple ways to store large bales of hay during these cold winter months. The best way to store hay is in some kind of structure (barn), but even there, a study by the University of Tennessee shows a 5 percent loss in round bales. Little of this loss is digestible nutrients, with the exception of vitamin A, which will be greatly diminished after a year of storage. When you place round bales outside, tarped hay on pallets had a 14 percent loss, while round bales that were net wrapped had a 23 percent loss. Even with those losses, uncovered hay had a 30 percent loss.
Getting the hay off the ground by the use of tires, railroad ties, pallets or even crushed rock helps. As much as 12 inches of the bottom of a bale can be lost through moisture wicking absorption. Ground contact can account for over half of the total dry matter losses.
Just how you store the bales involves other issues. Currently it is advised to have large round bales in north-south rows. This allows the sun to reach both sides of the bale and allows for drying during the day. To enhance this the rows should be about 3 feet apart. Also, these bales should be running down the slope of a hill and not across it to reduce the potential for rain water retention. Some would advise staying away from the top of the hill as this is the place for potential lightning strikes.
When I travel to South Dakota I see a lot of large round bales that are triple-stacked in a pyramid shape. The main reason this is done is for machines called stack haulers that remove over 20 bales at a time from the fields to hay yards for winter storage. The hay is placed in stacks in the field and these platforms work their way, using chains, under the bales and lift them up.
When hay is store like this, the water runs off the top bale down to the next and then to the next and increases spoilage. However, because of the lower rainfall averages of around 15 inches per year versus our 35, their losses are less than ours. But there still is greater loss in this method than individual rows. However, there are other considerations.
In the accompanying South Dakota picture, those bales have a second purpose—serving as a north windbreak around the cattle feedlot. As the weather gets warmer, the wind break decreases in size as it is being fed. This hay keeps cattle warm while digesting inside, as well as protecting them from the outside.
Occasionally, I see large round bales stored against the woods and under the trees. These would have even greater loss because they do not dry out. I also see bales where the bottom one is flipped on its end and another one is place on top in a "T" style. This allows the rain to still enter the ends of the bottom bale. Watch out for the weeds growing next to the rows, as these weeds help retain moisture around bales.
There is also discussion as to whether the bales in the row should be placed end to end or allow a space between. The University of Wisconsin says, "Densely packed bales shed more moisture than low density bales. Less damage occurs if round bales are stacked end to end. Net wrapping does not eliminate the problem but helps bales shed precipitation better than those wrapped with twine. Bales made from flat, grassy forage shed water better than coarse, stemmy alfalfa."
Because I do not have a barn to store hay, I have my dry, large, square bales run through an inline wrapper. For the most part, this has proven to be excellent storage. Occasionally, there has been moisture leak in from the bottom. When this happens, there is a definite mold area. That limited problem was worse last year. I do not know if it was wrapped better this year or just the lack of overall rainfall this year made the difference, as we are in an area designated as a moderate drought.
I have also used round bale sleeves. On my farm, that is a three-person job. One to operate the bale spear whether on the tractor or skid loader and two to put on the cover. You have to make sure the bale is not too big for the sleeve and also not too small, as it easily can flap in the wind. I have had mixed results with bale sleeves; some I could use twice over two years and others that did not come close to lasting the one season. Those ended up being ripped into smaller pieces and flying across the field.