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Wrapping hay

Jim Stordahl, Extension Educator, Ag Production Systems1

Weather predictions are easy to make but carry a poor warranty. With advances in computer modeling of weather patterns, developing a long-range forecast has gotten more accurate, but still tend to be very general and not site-specific. Mark Seeley, Extension Climatologist, says the latest models are suggesting a weather pattern for Minnesota similar to 2013, where it was wetter in the early part of the summer and dryer later in the season.

Preserving hay under challenging weather conditions

If the models are correct, that adds another challenge to preserving quality forage if you typically make dry hay. To harvest quality dry hay, several consecutive days of favorable weather are necessary. If Dr. Seeley's predictions come to fruition, harvesting a quality product from the first cutting of hay may be challenging.

Balancing forage quality and yield

Rain on cut hay can significantly reduce quality and yield. Depending on amount and duration, rain after cutting can reduce yield and forage quality up to 40 percent. The decline will likely be greatest if the rain falls on dry hay and considerably less if it falls on freshly cut hay.

Waiting for better weather also reduces quality, but increases yield. Alfalfa yield increases about 100 pounds per acre per day if growing conditions are average, except for the latest cuttings.

The quality of first cutting decreases at the fastest rate, while later cuttings change in fiber and digestibility at a slower rate. For example, the first cutting decreases about 5 points in relative feed value (RFV) per day, second cutting decreases 2 to 3 points per day and third or fourth cutting declines 1 to 2 points per day. Late fall growth may change little in forage quality during mid to late September and early October. Relative forage quality (RFQ) will change about the same as RFV on first cutting and then decline about 4 points per day on the 2nd, 3rd and 4th cuttings during the growing season.

Large bale silage

Large bale silage

Large bale silage

To deal with potential losses in forage yield or quality, livestock producers have adopted large bale silage as a method of harvesting their hay crop. Putting up silage bales, or "baleage" as many producers call it, that will store longer with less dry matter loss is one key to efficient harvest. Baleage is an alternative to storing dry hay and may be exceedingly helpful during rainy periods of the haying season.

Silage bales are easy to transport short distances and make a flexible addition into most feeding programs. Feeding baleage is similar to feeding dry hay, but will have less storage waste. However, baleage may not be feasible if long distance transportation is needed to market the hay. Since baleage can be as much as half water, transportation costs often become excessive.

Optimum moisture content

The ideal moisture content for baleage is between 40 and 55 percent. This will create a condition for proper fermentation and longer-term storage when the bales are wrapped. Dry matter losses will be lower when harvesting at these moisture levels. However, many producers end up in a moisture range between 20 and 35 percent and end up with "tough hay." Bales in this lower moisture range need to be wrapped to avoid spoilage, but may not ferment as readily. The key with all moisture levels is to keep the air out. It's a bit like canning pickles or tomatoes; one will ferment, the other will not, but the key to both is excluding the oxygen.

Plastic wrap thickness

Research in Wisconsin has found that at least 6 mls, and preferable 8 mls of plastic wrap cover the bale. This can be accomplished by wrapping 6 times with 1 ml plastic or 4 times with 1.5 ml plastic. With 4 mls of plastic, oxygen leaked through the plastic to support continued microbial growth and spoilage. Total plastic thickness, not the number of wraps, appears to be the most important factor to resist oxygen from reaching the feed. Line wrappers provide an opportunity to reduce plastic costs and wrapping time when compared to individually wrapped bales.

For optimum preservation, bales should be wrapped within 24 hours using 6 to 8 ml thick plastic. In a Wisconsin study, bales were wrapped at 12-hour intervals up to 96 hours after baling. Bales left unwrapped or where wrapping was delayed more than 48 hours exceeded internal temperatures of 130 degrees F°. These bales tended to have lower forage quality and greater mold throughout the bales.

Sizing bales

An important factor to remember is to make bales the size and weight for the wrapper and your loader. Most wrappers have an optimum bale length of 4 to 6.5 feet. If bale moisture is quite high, these bales can be quite heavy, so be sure your loader can handle the extra weight. Heavier bales also have more problems with plastic tears and holes while wrapping, stacking and in storage. With continuous wrapping (sausage style), this may be less of a concern. When you handle large, individually wrapped bales, use a bale grabber instead of a spear unless you plan to feed immediately.

Storing silage bales

Silage bales should be placed on a smooth surface free of sharp objects or crop stubble. Mowing a grassy, well-drained area is a great place to store silage bales. Be sure the area is away from fence lines and other obstructions, so removal is not hampered.

Harvesting high quality forage can be challenging during periods of rainy weather, but wrapping bales "wet" for bale silage offers producers one more option to achieve this goal.

1Jim Stordahl can be contacted at or 800-450-2465.


Clark, J. 2004. Making quality silage bales. University of Wisconsin Focus on Forage Vol. 6 No. 4:1.

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