Wrapping Large Bales for Dairy Cattle Saves Money

For handling large amounts of hay silage, nothing beats bunker silos for efficiency. But if your dairy farm's needs are more limited, wrapped bales might prove a better option. To wrap large square bales in tubes, two bales thick, custom operators typically charge $10 to $15 a bale.

However, there's a much less expensive approach. Using the same type of plastic that covers bunker silos, the Alfred College dairy barn team tested a system that could cost as little as $1.35 a bale the second year it's used. The system creates a plastic-covered silo divided into sections.

Each section holds enough feed for one week. Two six-mil-thick plastic films are used--One to create each section and another to cover the entire silo. As with any haylage system, the quality of feed it produces is good if you manage it properly. For this system to work well, it's critical that each section contains no more than what you can feed in one week. Otherwise, some spoilage may occur, especially during the warm season. Even with this precaution you may occasionally get white mould growing on the surface of bales exposed to oxygen, although it doesn't normally affect palatability. Using silage preservative may help alleviate this problem.Your first step is to calculate the number of bales you need every week for feeding. This determines the size of each section within the silo. To use plastic sheets 24 feet wide for the internal sections and 26 feet wide for the external covering, you need to have bales five feet long.

If your bales are a different length, shop for plastic first. If the silo site surface is concrete or asphalt, you don't need plastic under the bales. If you are storing bales directly on the ground, you need to protect them from contamination by the soil. Use leftover plastic or plastic that would be inadequate for covering the silo. This plastic can also help to keep bales covered during winter. Place bales crosswise, two wide and two high. Pack them as closely together as possible to reduce air pockets.

After you complete one section, cover it with the internal plastic sheet. The plastic is temporarily held in place while another section is added against the previous section. You need to insert the sheet for the next section between the sections. Repeat this process until you complete your silo. Then you install the second layer of plastic over the silo's entire length.

graphic of a plastic silo showing  plastic over large square bale held down by sand at each corner.

Figure 1: Diagram showing placement of plastic for silo.

Use baler twine to hold one tire on each side of each section. Let the tires hang one or two feet above the ground to keep the plastic sheet in place. Then carefully seal the plastic around the silo's base with fine sand.

The Alfred Campus trial used minimal equipment-one tractor and a wagon, and another tractor for handling the bales. One load brought 20 bales to the site, the number required for one section. Two people took one hour to complete one section that held 4.5 tons of dry matter. That included loading and unloading the wagon. Overall, 37 sections were constructed for a total of 740 bales harvested.

The total cost of plastic for the first year is $2,170 or $2.93 per bale. If you handle the plastic very carefully, you can reuse much of it the following year, thus reducing the cost per bale (see chart).

When removing the external plastic, cut it every 12 feet for pieces that can be used for ground cover under the bales, or every 24 feet to reuse it as internal film. You can reuse the internal plastic, if you handle it carefully, for the same purpose in following years.

The Alfred team estimated 90 per cent of the internal plastic could be reused the second year and 50 per cent the third year. After the first year, only the external plastic would have to be purchased, reducing the cost per bale to $1.35.

Tips For Success

  • Use a silage preservative at the time of bailing.
  • Calculate the number of bales you'll need for every week of feeding.
  • If you're very careful during handling, you can reuse much of the plastic the following year.
  • Use a piece of cardboard to protect the plastic from damages by the twine holding the tires.
  • You may use leftover plastic on the ground to avoid contamination from the soil.
  • Don't place the silo too close to a wall or another silo. Remember that you have to put sand around the base.
  • Don't place the silo too close to a fence line.
  • Choose a well-drained site; a long silo can be a potential dam.
  • Think about snow buildup.
Table 1. Cost of big square bale haylage using the section silo technique compared to conventional wrapping for 740 bales
  Internal Plastic External Plastic Cost Per Bale Total
Conventional Wrapping
Section Silo - Year 1 (all plastic purchased)
Section Silo - Year 2 (same plastic reused)

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