As this year’s silage harvest draws closer, farmers, harvesters, agronomists, and crews will be preparing to make the most of this significant investment. A crucial way to capitalize on the time, money, and energy spent on growing silage is to capture as much nutrition as possible — in other words, avoiding silage losses.
Loss occurs in the forms of improper fermentation and/or shrink, leading to fewer available nutrients. In a Penn State Extension “Bovine Banter” podcast, the University of Nebraska’s Mary Drewnowski discussed what farmers should focus on to avoid these losses.
Her number one recommendation was to get moisture content right at harvest. If silage is packed too wet, the beef systems specialist said we will lose dry matter to clostridial fermentation. If silage is too dry and doesn’t pack well, it will host more oxygen-loving bacteria.
The biggest contributing factor to silage losses is almost always density, she continued. Not reducing the oxygen level early enough to limit clostridial fermentation does not create an opportunity for forage to thrive.
To reach proper density, Drewnowski pointed to the 800-pound rule. That’s 800 pounds of tractor weight per hour of incoming silage weight. It won’t always be possible to achieve this level, especially with larger piles and forage arriving, quickly, but she encouraged farmers to get as much weight on the bunker or pile as possible.
Focus on what you can control, she noted. Think about everything you do to limit compaction in the fields and reverse those efforts. You can also control how thick the pile’s layers are. Drewnowski encouraged aiming for 4 to 6 inches per layer and measuring to monitor that benchmark. Making the slope longer gives you more opportunity to reach that goal, she added.
Losses after harvest
Shrink can occur at feedout but also begins before then with how silage is stored. Drewnowski said the floor of feed storage is not considered enough when considering loss. Whether you’re using a bunker or bags, placing feed on bare ground instead of concrete can result in up to 20% dry matter losses as feed is lost to mud, she cited.
This is one of the ways people often underestimate shrink. “If you track it, you’re probably still underestimating it,” Drewnowski said. Lost feed reduces dry matter and nutrient availability while adding moisture. Five percent shrink on an as-fed basis is like 15% on a dry matter basis, she described. And don’t forget that what you’re losing is often the best part of the feed.
Labor and time are typically the biggest challenges to investing in good storage, but Drewnowski encouraged all farmers to pencil out what poor storage can cost. Even in the case of a bunker or pile, loss occurs when the storage is sized improperly to the feedout rate. Every feed removal from the face lets in oxygen, so the goal is to remove at least 6 inches per feeding, she said.
“Poorly managed silage may be a situation where you shouldn’t be making silage,” she concluded.
