The changing landscape of dairy feed storage

Upright silos keeping silent watch over farms are a common sight and are generally accepted as a vital part of the traditional farm. However, the changing landscape of agriculture proves to slowly be putting these edifices out of commission. Upright silos on American farms have a long and rich history.

According to the United States Department of Agriculture, there were only 91 silos in the country in 1882. By 1895 that number had grown to more than 50,000 and by 1903 there were thought to be up to 500,000 silos across the nation. The quick rise in popularity of the silo shows there is more to the structure than just good looks, but silage bunkers and bags are becoming increasingly popular.

“We usually have less dry matter loss in an upright silo than with a bunker. For the uprights, it’s dealing with a smaller overall surface of exposure. With the bunker you have a larger face so you’ve got more of a chance of spoilage on feed out,” said Maurice Eastridge, a professor of dairy nutrition at The Ohio State University. “There are a few advantages, but when you look at overall cost and labor efficiency, we’re just going to see less and less use of those uprights.”

As dairy farms across the country are growing in terms of size and feed consumption, many operations are moving away from the once-popular use of upright silos. Eastridge says the issue of how silage is being kept is something that has changed significantly in recent years.

“Today what we’re primarily looking at are bunker silos and silage bags as favorable options,” Eastridge said. “If we have an upright system that’s in place, it’s making the most effective use of that while you can, and then when it comes to replace that or expand the operation, you’re probably going to be looking at bunkers or bags.”

Eastridge says there are several reasons behind the need to slowly work away from upright silos.

“When we look at storage, it’s very important that we have a system that will provide a very solid sealed fermentation system,” he said.

Labor efficiency and ease of use are other major areas of concern. According to a study by OSU Extension and Team NEO (a group dedicated to facilitating business in Northeast Ohio), almost 35% of dairy farms in the region are planning to increase herd size within the next five years. One of the variables outlined in slowing that growth was lack of labor, showing the importance of a less labor intensive feed storage system.

“Upright silos are slow to empty. In terms of managing the unloader, it is kind of difficult. Whereas you look at a bunker, it’s a person driving a tractor or a front-end loader and putting the feed into a feed mixer. Then the bags are the same in terms of labor efficiency,” he said.

There are also significant cost advantages to consider.

“When you get down to comparing the uprights versus the bags and the bunkers, you have to think about cost of construction and the volume of feed that’s needed today with the size of many of our operations, and the uprights just won’t come into play there,” Eastridge said.

Eastridge also pointed out the issue feed bunkers pose when it comes to flexibility. Because feedbags are not permanent structures, their use each year can change depending on the farm’s demand. In addition, construction costs will not rely on a certain size as much as when silage bunkers are constructed.

“The benefit to the bags over the bunkers is you will usually have a little bit less dry matter lost in the bags and they also provide flexibility based on the amount of feed that you need in any given year,” he said. “The dry matter losses from bags are a little bit less than the bunker silo. With proper additives and coverage today, we can probably get dry matter losses under 10% on bunkers but more likely, it’s 15% to 20% losses. Whereas on the bags, our losses are in the 5% to 10% area.”

Eastridge said when comparing these options for silage storage, bunkers do offer some key advantages of bags.

“The nice thing about a bunker is it’s a fixed construction, you know its dimensions, and it’s there to fill as you need. You don’t have to fill it completely but you have some struggles there if you don’t fill it completely. How you are going to minimize losses off the face?” Eastridge said. “The tendency today by some operations is to maybe build it a little bit too big and they have too big of a face and then some quality issues on feed out. With a bag, the nice thing is you have a small surface and it’s easier to maintain the quality both during fermentation and feed out.”

Safety is another issue when it comes to comparing the different feed storage options. There is danger in all feeding options because of the common rush during harvest season, though bunker silos do have a potentially more dangerous element to their use because of the need to pack down the feed.

“We have to also be mindful of what harvest conditions that we want in the feed depending on the kind of structure it is going in,” Eastridge said. “If we’re going into an upright, we have a little more margin that we can deal with in terms of dry matter of the feed and still get good quality out of it. For bunker and bag, we have to have that pretty moist to get good compaction or we’re going to get poor fermentation.”

There are many other dangers offered by uprights when compared to bags or bunkers, including harmful gases.

“The equipment on the uprights, when it’s working fine, it works great. If it’s not, there’s a risk around filling time with gasses. Without proper ventilation, the nitric oxide and so forth can be lethal,” he said.

John Lemmerman, manager of the Waterman Dairy Center at OSU, has done away completely with the use of their upright silos. The farm is now totally reliant on silage bags to feed the 100 Jersey cows.

“One of the main reasons we switched over from the uprights to the Ag-Bags is mainly safety for our students,” Lemmerman.

The heavy requirements for students to learn harnesses and other safety protocols were influential in their decision to phase out the tall structures. Lemmerman says the bags are superior to uprights in many ways but they still aren’t perfect. A big issue with the heavy plastic being used is their susceptibility to wildlife ripping holes in them. Lemmerman said that although you have to pay for a new bag each time, the relatively low cost outweighs the amount of feed wasted to exposure.

“We get just as good of quality, sometimes better quality, out of the bags. Depends what wetness you put it in at, but you have a little more variability with the bags,” Lemmerman said. “Usually if we can keep the bags going throughout the whole time with no holes and get them patched right away, we won’t have any waste as we go through, Obviously you’ll have some with birds and stuff falling down and a little bit of waste loading compared to the upright silos where it goes directly into the mixing wagon.”

He pointed out that the big difference between the farms using bunkers versus bags is the size of the operation. The expense of creating an entire structure devoted to the feed is more of a commitment than silage bags.

“How many we’re feeding we can vary. Right now we’re at 9-foot bags so we’re not too wide,” he said. “We can use bigger portions or cut back and not waste any of the face of the bag so that works out well for a smaller herd like us. A lot of the big farms can go to those bunkers and get them in there packed full quickly. The bags work better for the smaller farmers, typically.”

In the end, he said it’s nice to have an upright silo around for people to see but from a profitability standpoint, the general swing of dairy farms is moving away from the once-popular tall structures.

“It’s what everybody pictures with the farm and most of them keep one around. We’re keeping one around just for aesthetics, just so people can look at and identify the farm,” Lemmerman said. “They’re nice to look at but I’m glad I don’t have to climb them anymore.”

Check Also

Waiting on the proper soil conditions

On this week’s Pioneer Spring Agronomy Update, Dave Russell visits with Pioneer Field Agronomist Alex …

Leave a Reply

Your email address will not be published. Required fields are marked *