2010 was generally a good hay production year. We had a good growing season with timely rains. The kind of environment we had last summer allows for good harvest conditions. But then came September and a lot of wet weather. Many of our round bales that were stored outside without a lot of cover ended up with excessive rain that maybe left at least the bottom part of the bales standing in water and with the onset of very cold weather in November saw many of the bales frozen to the ground.
So where does this leave us for the rest of the winter? When harvesting hay it is not always easy to control weather related losses. But we can control storage losses by utilizing or investing in covered storage. As you drive around the countryside, you can see round hay bales standing outside and they have been covered by snow for a long time. Is this a big deal? In a word "yes". Here's a comparison on the effect of storage method on storage dry-matter losses. This information came from the University of Wisconsin's Forage website.
Storage Method% of Dry Matter Loss
Under Roofunder 10%
Plastic wrap-on ground5%
Covered on pad or elevated12-17%
Uncovered on pad or elevated20-46%
Covered on ground23-46%
Uncovered on ground45-61%
Check that last number 61 percent potential dry matter loss! Basically this hay has turned to manure. To put storage losses in perspective, let's assume that you store your hay outside and have a fairly reasonable storage loss of 10 percent. That may not sound all that bad, but a 10 percent storage loss means that for every 10 bales of hay that you harvest, you really only have the equivalent of 9 bales of hay to feed. Do the math on the 61 percent storage loss and you can see that you have lost over half of the feed value that you worked so hard and invested so much money into making the hay. It makes an investment into good hay storage seem cheap in comparison.
Dry matter loss is a function of hay moisture, temperature, and the length of time hay is exposed to these conditions. Large losses can occur in a short time frame under high moisture and temperature conditions. However, you can end up with similar losses by storing dry hay in a cool barn for an extended period of time. The message here is to invest in some sort of covered storage or method of covering your bales to insure that what you harvested last summer with still be there when you come to feed it or sell it later on this winter or next spring. Feeding quality falls off fast when we have bales standing in water or covered with snow and then subjected to fluctuating moisture levels when the snow melts in the spring. The same goes for harvested bedding material such as cornstalks or baled straw. What you harvested last fall will not be there when you want to use it or sell it if it is not properly stored in a cool dry place.
Another question that comes across my desk is the comparison between round and rectangular (big square) bales. This question was addressed as part of a study by the University of Minnesota. This study showed few differences in storage losses between round and rectangular bales stored uncovered on bare soil, over an eight month period. Both types of bales lost about 23 percent of the total volume of the bottom bales due to re-wetting. Round bales at the top of the pile did shed water better, but the study showed that the water simply ran off the upper bales onto the lower bales causing similar damage.