Tuesday, December 4, 2007

Evaluate Hay Storage Losses On Large Round Bales

by Rory Lewandowski
Storage losses in any hay production system are unavoidable, but what level or degree of loss is acceptable with a large round bale? Like the answer to many questions, it depends. It may depend upon the price/availability of hay, how storage losses affect animal performance, alternative storage options, and may even boil down to the goals/objectives of the producer.

A drive around the roads that surround the fields and farms of Ohio will reveal a common sight; large round bales stored out in the open in fields and farmyards. Bales stored in this manner and exposed to the elements develop a weathered layer. The depth of the weathered layer and yield loss associated with outdoor storage of bales depends upon both weather and site conditions. Yield loss is highest on bales in direct contact with the ground and in situations of high rainfall and/or where water can collect in the bale storage site. This weathered layer can represent a significant loss in terms of yield if animals refuse to eat it. The loss can be 10 to 16% for a 2-inch weathered layer, and 31 to 44% for a 6-inch weathered layer. For more details on percentage losses due to weathering see the University of Kentucky Extension publication entitled “Round Bale Hay Storage in Kentucky”.

Even if cattle will eat the weathered layer, it still represents a loss in forage quality with digestibility decreasing and fiber concentration increasing as compared to the unweathered interior portion of the bale. Weathering can cause a 16 to 22 unit drop in percent digestibility.

In years like this, with forage in short supply, it is hard to see these kind of losses due simply to weathering from storing bales outside. In years when hay is abundant and/or can be purchased cheaply, more hay can be fed to make up for the losses and the hay that is not eaten might even be thought of as a cheap source of nutrients. However, it is much harder to justify these losses when hay is expensive or extra hay is not available to feed. Producers may want to think about other storage methods to reduce dry matter and forage quality losses.

As might be expected when comparing storage options, bales stored outside on the ground have the highest dry matter losses. Up to 35% of the bale dry matter can be lost. By selecting a well drained site and getting bales out of direct contact with the ground by using pallets, tires, crushed rock or other materials, losses may be reduced to 25%. Using net wrap on outdoor stored bales instead of twine can reduce losses by another 10%, bringing the total dry matter loss into the 15 to 25% range. In terms of storage options that have been found to result in the lowest dry matter losses, plastic wrapped bales, bale sleeves, bales stored on a pad with a tarp, or a roofed structure have all been found to keep dry matter losses in the 4 to 7% range.

When deciding what storage option to use, factors that should be considered are: cost of the storage option, price of hay, environmental impact, and your goals/objectives as a producer. According to the University of Kentucky publication mentioned previously, a storage structure can be built for anywhere from $37 to $80 per ton depending upon the design and materials used. I know producers in Athens County who have used lumber cut and sawed on the farm combined with some re-used roofing materials to build some in-expensive hay storage. If this structure has a useful life of 20 years, then (using the University of Kentucky numbers) this figures out to $1.85 to $4.00 per ton per year in storage cost. Plastic wrap and net wrap are listed at a cost of $3.00 per ton. This would also be the yearly cost per ton since these materials are not re-usable. Twine tied bales stored on the ground outside are listed at a yearly cost of $1.50 per ton.

Now we need to figure the storage costs in terms of dry matter (DM) saved with relation to the price of hay. For the purposes of this example, lets assume dry matter (DM) losses of 25% for twine tied hay stored outside, 15% for net wrapped hay, and 5% for plastic wrapped hay and hay stored inside a structure. Let’s look at the economics if hay price is $40 or $60 per ton. The results are shown below:
After subtracting the cost of net wrap, plastic wrap and structure from the savings/ton column, all of the alternative storage options pay for themselves by reducing storage dry matter losses, even at a hay price of $40/ton. The greatest savings are made by the plastic wrap and structure storage options. Choosing which of these to use might come down to an environmental consideration or cash flow situation.

Plastic is dependent upon petroleum resources, and can only be used for one year, so disposal must be thought about. A structure is probably more environmentally friendly, but it might be easier for some producers to come up with the dollars needed each year for plastic wrapping as compared to coming up with a large one-time dollar expense for a structure.

Finally, the decision on what type of round bale storage is used may come down to individual goals/objectives. If the cattle operation is more of a hobby than a business, the losses may not matter as much, or, if hay costs get excessive, it may be easier to sell off animals rather than think about putting dollars into alternative storage options. Possibly the producer is approaching the end of his/her cattle production life and does not want to invest in any long-term costs. On the other hand, the producer may be in the cattle business for the long haul and willing to make long-term investments to improve the economics of the enterprise.
Regardless of the decision that is made, cattle producers need to be aware of potential storage losses when using large round bales and the options and economics of various storage systems.

Reference: Round Bale Hay Storage in Kentucky, Publication AGR-171