Of all the challenges in agriculture, making dry hay is one of the greatest. You need at least three, but more like four, days in a row to harvest dry hay. Unlike other crops that you can harvest a few hours after a 10th inch of rain, that causes another day’s delay in making dry hay.
As I write this today, it is pouring rain outside, even through the weather forecast called for only a 10% chance of rain. There goes some good hay as it gets a good washing. One way to make baled hay in only a two-day weather window is to make baleage.
Baleage is harvested at 65% moisture or less, with an ideal moisture of 45-55%. Baleage can be made down to 25% moisture, but that is not ideal. When baleage is made at either end of the moisture range of 25-65% it may not ferment correctly, and needs to be monitored closely for poor quality.
Eyes and ears
Monitoring of fermentation and forage quality is critical. Baleage often has a pH above 5 and low lactic acid values. The first line of fermentation monitoring is your eyes and nose. If you see a spoiled spot, or the smell is different than other bales, do not feed that one. Baleage should smell good; high butyric acid will smell very putrid.
Also watch for holes in the plastic, as bales close to these areas are at increased risk for botulism. Bales that are wet and seep effluent or squat during fermentation also undergo undesirable fermentation and are a risk to your livestock.
Analysis
Another tool is a fermentation analysis. The first measurement is a simple pH analysis. The goal is a pH below 5, which inhibits secondary fermentation by Clostridial bacteria.
A pH above 5 does not mean the bales need to be thrown away, but is an indicator that additional testing may be warranted, especially if the hay was baled too wet, has high ash content or has high butyric acid levels.
Butyric acid levels should be less than 0.5% on a dry matter basis with possible intake depression beginning at levels of 0.3%. While there are many strains of clostridial bacteria one of them, Clostridia botulinum, causes botulism. Clostridial bacteria ferment sugars, lactic acid and proteins and often produce high levels of ammonia.
The next acid level to check is acetic acid, which should be under 4% DM with a goal of 1-4% DM. Acetic acid inhibits yeast and mold growth and helps keep baleage from spoiling during feed out. High acetic acid often occurs in very high moisture hay above 75% or when bales ferment slowly due to high protein content or loosely packed bales with lots of entrapped oxygen.
Propionic acid is another one to monitor with a goal of less than 1% DM basis. High levels of propionic acid are an indicator that your forage did not have sufficient levels of available plant sugars for fermentation. Lactic acid is the goal of good fermentation; it is the product of anaerobic fermentation of soluble sugars and carbohydrates.
The goal is to have a minimum of 3% DM basis of lactic acid. It should be the dominate acid in well-fermented baleage, with greater quantities than acetic, propionic or butyric acid. Achieving 3% or greater lactic acid is difficult though, due to the long particle length and slow fermentation of baleage.
Besides acids, you can also check the Ammonia-N percent of total N, which is the proportion of that nitrogen in the forage that is present in the ammonia form. Levels above 15% indicate that some clostridial fermentation has occurred. Elevated ammonia levels are strongly associated with high butyric acid levels.
From a standard forage analysis, ash content can also be a sign of problems. A standing crop has 8-10% ash DM basis, with levels greater than 11% indicating that the baleage has been contaminated with soil, which can be the seeds for yeast and mold growth. Cereal grain forages are at a greater risk, especially when planted conventionally.
The wider the row spacing, the greater the chances of soil be picked up during the mowing and raking process.
Tips
While there is a lot to watch for when making and feeding baleage, it is an excellent tool to speed up the hay making process. Just be sure to make it at the correct moisture, not too wet. Make as high-density bales as you can to limit oxygen content in the bales, and wrap them as soon as possible after baling.
