Silage is a staple for many livestock producers as it’s important for keeping herds healthy and lowering feed costs. However, without proper management, silage can have excessive dry matter loss which lowers feed quality and even damages herd health.
In light of this, producers are faced with the question of whether covering their silage pile is really necessary or worth the cost. For example, an 80-by-140-foot bunker silo with concrete sides (includes a 5% overlap) would cost about $1,344 in plastic according to Dairy Herd Management without the cost of tires or man hours.
While investing in a tarp seems like an extra expense, it's actually a crucial step for limiting oxygen and successful fermentation. In fact, covering your pile surpasses face management in terms of importance.
Covered vs. Uncovered Silage Piles
Research shows that uncovered silage piles can result in dry matter losses between 8% to 46%. When silage is exposed to oxygen, it allows for aerobic non-beneficial microbes to break down nutrients and generate heat leading to higher spoilage and dry matter losses.
Additionally, these losses can create a 6-inch mold layer, which translates to 1-2 feet of the original silage pile. In other words, about 15-20% of the silage material is lost, meaning you’re essentially throwing away profits.
To put in perspective, that same 80-by-140-foot bunker silo without the $1,344 in plastic would have a 30% dry matter loss which would equal 201.6 tons of as-fed silage. For corn silage, that’s worth $50 per ton. Meaning, the total loss would be at least $10,080.
Oxygen: Your Worst Enemy
The biggest difference between silage and compost is oxygen. When oxygen enters the pile, it activates unwanted microbes such as mold and yeast spores that start to regrow, consuming nutrients and releasing heat and CO2.
This process rapidly raises the pH and opens the door for other microbes to grow, causing dry matter loss and low-quality feed. Volatile fatty acids (preserving acids) can also be released into the air when oxygen enters the pile, further degrading the quality of the silage and leading to even more dry matter loss.
Oxygen exposure can also happen at feed out leading to secondary decomposition. Secondary decomposition occurs when air enters the silage pile, activating surviving mold and yeast resulting in up to 10-20% dry matter loss in just a few days. It’s recommended to feed at least 8-12 inches of exposed silage a day to stay ahead of oxygen exposure and dry matter loss.
In some cases, animals can reduce intake or even refuse to eat portions of the feed. Issues such as hot feed, poor feed quality, texture or odor can lead to reduced intake and low milk production and weight gain in livestock.
How to Lock in More Silage Nutrients
Bottom-line, the best way to prevent dry matter loss and lock in more nutrients is to cover your silage pile and manage oxygen exposure.
A tarp will help keep oxygen out of the pile and limit harmful microbial growth. An inoculant can also be added to ensure fast and efficient fermentation. Look for an inoculant with bacteria that start to work in oxygen-rich environments and a high pH. This ensures that the pH of your pile will start to drop immediately, even before any remaining oxygen is completely eliminated.
Agnition’s Anchor™ for Silage is an advanced inoculant blend powered by Microbial Catalyst® technology and cased in a unique encapsulation process. Anchor not only safeguards inoculant bacteria during storage but also boosts their effectiveness in silage. When activated in water, each inoculant granule easily dissolves and quickly goes to work to rapidly drop pH for effecient fermentation.