Adequate hay storage is critical so livestock producers can minimize the loss in both value and nutrients of their hay, which makes up a large portion of their annual feed costs.
"Stored forages provide essential nutrients primarily in winter or when pastures are inadequate and are a consistent feed supply for livestock. However, some of these nutrients can be lost if forages are not stored properly," said Shannon Sand, SDSU Extension Livestock Business Management Field Specialist.
Types of storage losses
Hay stored in a barn could have around a 5 percent loss, whereas, that stored outside uncovered could have 30 percent losses due to spoilage. Table 1 shows some of the different types of hay storage available and the percentage of expected losses between nine months and one year.
"Barn-stored hay usually has higher nutritional value and little spoilage compared to that stored outside," Sand said.
She explained that hay stored inside allows for a reduction in contact with soil and moisture thus reducing spoilage. Some disadvantages of indoor storage are unwelcome animals, such as skunks, raccoons and other animals. Storage space is limited, and bales must be stored carefully to prevent falling or exerting too much pressure on the sides of the barn. Sand said that the initial investment in the storage building is also an important item to consider.
Increased storage space is one of the advantages to storing bales outside. Some disadvantages to outdoor storage that Sand listed include: potential spoilage and decreased nutritional value. She said to avoid spoilage, it is best to store hay outdoors on gravel or pallets end to end in north-south rows.
"Outdoor hay storage areas should ideally not be in a flood plain and with as little shade as possible, to prevent spoilage," Sand said. "It is important for producers to remember, hay must have proper drainage, sunlight penetration and airflow between rows to facilitate drying."
Hay bales left uncovered can lose 5 to 20 percent of its original weight to dry matter losses in nine months. Elevating bales reduces losses by 3 to 15 percent. "If a producer does not have a barn available to store hay the best option is to cover and elevate the hay," Sand said.
By elevating and covering the hay, Sand said the maximum loss could be 2 to 4 percent, which is similar to barn-stored hay.
For hay bales stored outside weathering is normal. Table 2 shows the percentage by volume of round bales according to the inches of weathering present. Weathering on the outside of the round bales (a few inches) accounts for a large portion of loss from the total bale.
"It is important to try and feed outside stored bales within nine months because of their loss in nutritive value," Sand said.
Many producers, Sand said will typically store higher value hay in barns and lower value outside. She added that it is important to calculate the costs associated with storage loss depending on the storage system. "The cost of the alfalfa/grass hay the producer is $85 per ton. The initial cost of 250 tons of hay is $21,250," she said. Table 2 shows the different methods of hay storage and the additional hay needed to meet the producers feeding requirements.
Table 3 shows the additional hay need and the costs based on the expected spoilage rates.
"This table also shows the cost differences between storing hay in a barn compared to the alternatives. Because of its low quality losses storing hay in a barn is the best solution available," she said. However, Sand added that this is not always a feasible option for some producers. If this is the case, producers can look to other options.
"Hay stacked with a tarp and on tires or pallets is the next best alternative when comparing the differences in the additional cost," she said. According to Table 3, Sand said the best long term solution for the producer would be to invest in a barn for hay storage. "However it's not always feasible for producers. No matter what type of storage is being used, dry matter losses are always possible. By following the recommended storage methods, and careful handling, losses can be minimized saving livestock producer's money," Sand said.
Table 1. Different types of hay storage and the percent of loss

Type of Storage Percent Loss (%)
Hay Barn 5
Stacked and Tarped on Tires or Pallets 14
Plastic Sleeve 19
Net Wrap 23
Outside Uncovered 30

**Data is from study conducted at the University of Tennessee1
Table 2. Percentage of bale volume affected by weathering.

    Depth of weathered layer in inches
Bale Dimensions 2 4 6 8
Diameter Width % of bale volume weathered
4’ 4’ 16 31 44 46
5’ 4’ 13 25 36 46
6’ 5’ 11 21 31 40

Table 3. Additional hay needed and associated costs

          Compared to:
  Additional Hay Required (tons) Added Hay Cost  Barn Tarped  on Tires & Pallets
  Initial Short Need      
Hay Barn 250 13 261 $1,105 $0 -$2,975
Stacked & Tarped
on Tires or Pallets
250 35 283 $2,975 $1,870 $0
Plastic Sleeve 250 48 296 $4,080 $3,320 $1,105
Net Wrap 250 58 306 $4,930 $3,825 $1,955
Outside Uncovered 250 75 323 $6,375 $5,270 $3,400

 

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