Making premium quality dry hay requires a 3-4 day stretch of premium weather when the forage is of premium maturity, which can sometimes be hard to come by in Ohio and other parts of the Midwest during the spring. Therefore, baleage, or wet wrap, gives the weather some grace. The beauty of baleage is that you can cut one afternoon and bale the next day after the dew lifts. Odds are that finding a 2-day, rather than a 4-day, window will likely enable you to capture the perfect maturity of the forage you’re growing. Additionally, the fermentation that occurs improves digestibility for the animal, meaning they’ll get more nutrients per mouthful.
Making baleage is essentially like making mini silage bales using grasses, legumes, or small grains. The forage is mowed like you would for dry hay, but curing time is less as optimal moisture content is between 40 and 60 percent rather than the 12-20 percent for dry hay. Once bales are made, the entire bale is wrapped in 6-8 mils of plastic to exclude oxygen from the forage. Excluding oxygen starts the microbial fermentation process that breaks down plant sugars into acids and improves digestibility of the forage.
When harvesting forages, there is a sweet spot between forage quality and yield. When quality is high, yield would be quite low as the plant is still relatively immature. However, when the yield is very high, quality decreases as plants age and become woodier. For grasses, the sweet spot for harvest is at the boot stage or just as the seed head is emerging. 10% bloom is appropriate for legumes. Small grains need to be baled before the boot stage because once the seed head emerges, there will not be enough fermentable sugars throughout the whole plant. As plants mature, they will become stemmier with increased amounts of lignin. Lignin is indigestible and reduces the amount of usable nutrients. Further, a lot of stems can prevent you from making a nice, dense bale and can alter the degree of fermentation because of potential air pockets.
Wrapping baleage within 12 hours of baling will attain the greatest level of forage preservation and mold prevention. The wrap for baleage is a polyethylene plastic film between 1 and 1.5 mil thick, or 1 and 1.5 one-thousandths of an inch. The wrap can be white or black, but white is more popular because of its ability to reflect rather than absorb the sun’s heat. Regardless of the color used, each bale should have at least 6 mil of plastic covering to exclude oxygen. Allow the bales to ferment for at least 4 weeks before feeding to allow pH stabilization.
For bales that are too dry, or less than 40% moisture, the bale will be less dense than wetter bales and will probably have air pockets, setting up the bale to mold. Likewise, when bales are too wet, butyric fermentation can occur and create a risk for disease.
Diseases that can occur from spoiled baleage include botulism and listeriosis. Botulism is caused by toxins formed by Clostridium botulinum. It presents as muscle weakness as soon as 24 hours after ingestion. It will eventually progress to downer cattle or sheep and death from suffocation. Botulism will paralyze the diaphragm and prevent the cow from breathing. The tongue may also droop from the mouth. Listeriosis is another disease of the nervous system caused by Listeria monocytogenes. It is also called circling disease because of the tendency to lean to one side and circle in that direction. Additionally, face paralysis will occur, preventing the animal from eating or drinking. Abortion may also occur in listeriosis cases. Unfortunately, botulism is always fatal and the chance of recovery from listeriosis with early and intense antibiotic treatment is only about 25%.
You can test the baleage for safety prior to feeding. A pH test to measure the acidity of the baleage will give an idea of the fermentation quality. The pH should be 4.5 or less and baleage above this, and definitely above a pH of 5, will have increased chances of clostridium and listeria presence. You can find a decent pH meter online for less than $100 if you’re concerned about disease. Alternatively, sending core samples to a feed laboratory after fermentation is complete will yield pH, nutrient values, and fermentation products of interest, such as butyric acid.
Baleage has its pros and cons, just as dry hay does, so before making the switch, look at your operation and decide if this change is right for you and your stock.
Haley Zynda is an OSU Extension Agriculture and Natural Resources Educator and may be reached at 330-264-8722.
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