Making a large bale of haylage lowers spoilage

Gary Sliworsky
Ag. Rep.

Following is part 1 of a two part article on baleage tips provided by Joel Bagg, Forage Specialist with OMAFRA.
Making large bale haylage, also known as “baleage”, reduces weather risk and can result in very high quality forage. However, the risk of spoilage can be frustrating. “Baleage disasters” can sometimes result in a total loss. Extra care is required when making baleage to avoid mouldy feed.
Baleage does not reach as low a pH as chopped haylage, so there will always be an increased risk of spoilage. There are many management factors that contribute to a consistently good fermentation of wrapped baleage and the subsequent “keeping ability”. The consequences of making mistakes are additive and interactive, so it is sometimes difficult to pinpoint why some baleage spoils while other baleage does not. Here are a few points to consider:
Avoid trying to make baleage out of mature hay with a low sugar content. Sugars are required for a good fermentation with adequate lactic acid production and a low pH. Also, stiff coarse stems can more easily puncture the plastic. Wrapping mature, coarse, stemmy baleage is often disappointing. It won’t turn poor quality forage into high quality baleage, and this makes the added cost of wrapping more difficult to justify.
Avoid using haylage that was rained-on. Sugars are leached out and are not available for fermentation. Rained-on windrows also become contaminated by soil borne clostridia bacteria which is splashed up by the rain, resulting in a poor fermentation. For the same reason, if possible, avoid raking to minimize contamination by clostridia bacteria. Do not use fields contaminated by manure, and avoid cutting too close to the ground.
Early-cut grasses often ferment more easily than alfalfa or red clover because they have more available sugars, and have less buffering capacity which makes it easier to lower the pH. This helps to explain why second-cuts, which are usually mostly alfalfa, are sometimes more difficult to ferment successfully and have a higher risk of spoilage.
Make uniform, firm, tight, dense bales. These bales have less oxygen in them and allow less oxygen penetration. Large square bales are typically more dense than large round bales. Size bales so that they are not too heavy for the available loader tractors to handle, or too big for the wrappers. Heavier bales are more difficult to handle without tearing plastic. Plastic twine is preferred over sisal twine to reduce plastic wrap degradation. With continuous wrappers, bale uniformity is important in order to avoid air gaps between bales. Use windrow and baling techniques to maximize bale density and uniformity. These include wide uniform windrows (no barrel-shaped bales), slower baler ground speeds, and using large square, hard core and round-silage balers with precutters.
The recommended moisture for wrapped baleage is generally 40–55%. Moistures greater than this result in bales that are too heavy. Excessively wet bales increase the risk of clostridia spoilage with butyric acid production, resulting in sour, foul smelling, unpalatable baleage. Wet bales are also more prone to freezing.
Some producers have had success when wrapping large bales as “low moisture baleage”.