top of page

Storing large round bales

Hay, I mean,'s a new article on "Storing Large Round Bales". I thought it was a significant study. Proper Hay Quality Evaluation being one of the least-discussed topics in my world. I'm surprised at how many graziers neither know how to evaluate hay quality, nor are they likely to send in samples for determination of true nutrient density and quality. Dairy farmers do it all the time.

The only thing I wonder about is why these researchers measured hay loss relative to weight loss? At first glance one might assume that the hay is just getting dehydrated. On the other hand, I know that other university studies correlate weight loss in hay with loss of true Dry Matter (DM) and subsequently loss of vital nutrients (see The latter is probably more true.

Hay put up with >20% moisture will "sweat" that is get hot, both due to continued plant respiration (some of it is still alive even though detached from the mother plant, just like fruit, veggies and salad leaves in our refrigerators!) coupled with microbial action. This sweating will jack up the heat in the bale which increases destruction of nutrients. With really wet hay it could even smolder or catch on fire. Wet hay is a "mold factory" too, and this is the true root cause of most of the pinkeye, footrot, you-name-it, any parasite infestation or infection, both of which actually a derivative of immune compromise. I remember back in the small square bale days how hot those tightly-packed bales can be, even in the middle of the winter, big bales are even worse. Feeding that hot hay to horses is a risk for colic, and probably has similar actions on the rumen. Much of it has dusty mold too which is also a horse crippler. We used to let it sit for a month before giving to horses. Most horses where I work are on hay 12 months a year (because the pastures, if they have any, are allowed to be ruined by the horses!).

My concern for losses of hay quality are primarily 1) increased MOLD mycotoxin, and 2) Decreased Nutrients in stored forage. I think the study is correct to presume that we can avoid the REAL problems with hay, which, to me is mold and lost vital nutrients. If they heat hits or exceeds 130 degrees F there will be significant destruction of plant enzymes and vitamins. Fire danger can begin as low as 150 degrees F. We used to determine hay quality by cutting open a bale and immediately putting our nose right into the center of the bale. Good hay smells sweet and glorious, moldy hay smells like something else, some say sharp, musty, or "metallic". I think people who are not augmenting their winter forages (of any quality, good or bad) with free-choice supplements well-fortified with VITAMIN A, D3, and E are begging for trouble. Check your mineral tag, it should be close to 800,000 IU/# of vitamin A, if not higher. Low fat soluble vitamins from stored forages are one of the main causes of spring animals looking shabby and shaggy, then getting parasites and disease. They are equally shabby on the inside too, we just can't see that (until it's too late).

Perhaps the ONLY positive result of the drought is that we have less moldy hay in those areas. Meanwhile, thanks to what might be Global Weirding, we are having wetter summers where I live as well this happening in many other normally wet areas. So BALEAGE has been the salvation. (cut hay lying on the ground is always one of the best ways to make it rain. Second only to washing your car or, of course, planning an outdoor picnic). However, if your hay is LOW BRIX, you are still in trouble because if it's <10 brix it probably won't ensile in the bag and will subsequently mold or even rot. Rotted grass is an anti-nutrient. I like to see molasses sprayed on low brix hay before baling or bagging. It can also be injected into the bale, but that is far less likely to be adequately distributed. Something is lost with ALL stored forages, whether it's pickled or whether it's dried. You just have to pick your battles.

Here's the study.....

The very dry spring (that most of Oklahoma has endured) points toward short hay production this summer and expensive hay feeding next winter. As hay is being cut and put in large round bales, it is very important this year to reduce hay storage losses. University of Tennessee animal scientists conducted a trial to compare different methods of storing large round bales of grass hay. The hay was cut and baled in June in Moore County, Tennessee. The bales were weighed at the time of harvest and storage. Then they were weighed again the following January at the time of winter feeding. The following table lists the type of storage and the resulting percentage hay loss.

Table 1. Losses of hay stored using six methods of storage

(Source: Dr. Clyde Lane, University of Tennessee Department of Animal Science)

Type of Storage Percentage (%) of Hay Loss

On ground, no cover 37%

On old tires, no cover 29%

On ground, covered 29%

On old tires, covered 8%

Net wrap on ground 19%

In barn 6%

Average spring, summer, and fall rainfall in Tennessee will generally be greater than that experienced in much of Oklahoma. However the rankings in storage loss between the storage methods will be present in Oklahoma as well.

An Oklahoma State University fact sheet by Dr. Ray Huhnke summarizes differences in storage loss that can be expected in an Oklahoma ranch setting.

Source: Oklahoma Cooperative Extension Fact Sheet BAE-1716 “Round Bale Hay Storage”.

Table 2. Percentage (%) dry matter loss of round hay bales.

Storage Method Storage Period

Up to 9 months 12 – 18 months


Ground 5 - 20 15 - 50

Elevated 3 - 15 12 - 35


Ground 5 - 10 10 - 15

Elevated 2 – 4 5 -10

Under roof 2 - 5 3 - 10

Enclosed barn Less than 2 2 -5

Obviously, it would be ideal to store the hay inside, but that will not often be practical. The next best option is when the hay is stored on something that gets the hay off of the ground under a rain shedding cover.

Featured Posts
Recent Posts
Search By Tags
Follow Us
  • Facebook Basic Square
  • Twitter Basic Square
  • Google+ Basic Square
bottom of page