Part of an educational series by CAE Farm Business Planner, Silene DeCiucies, to help the everyday Vermonter understand the ins and outs of farming in our brave little state. Photos by Silene DeCiucies, unless otherwise noted.

As our forests and fields become blanketed in snow, grazing becomes difficult, but the local livestock population still requires vast amounts of forage in order to get through the long winter and keep making milk and meat for us. They are snacking on forage grown and harvested in the summer months and stored in a number of ways to be used throughout the year. 

Most Vermonters know something about dry hay and the process of making it, and many have heaved countless bales into kicker wagons or haylofts. Putting up dry hay has been done for centuries and is still the primary form of hay storage in parts of the world and continues in Vermont. It takes days of sunny weather and careful handling from the field to the barn to preserve a crop in this way. However, forage crops preserved and stored by high moisture, fermented methods dominate what is fed to dairy cattle and ruminant livestock in Vermont.

Northeastern Vermont's humid climate and small fields can make drying hay, especially the high-quality hay milking dairy cows require, difficult. Likewise, our short growing season makes it hard to grow and then field-dry a crop for grain corn (a heat-loving plant derived from the Mexican plant teosinte) as is standard in hotter climates. Since at least the 1940's, Vermont farmers have experimented with various methods of preserving forages-overwhelmingly hay crops and corn-through ensiling or silage-making. Sometimes referred to as "pickling," this involves storing the cut plant only partially dried in an environment that limits oxygen. 

FARM VOCAB

Silage: Grass or other moist plant matter compacted and stored in airtight conditions to ferment.

Cows enjoying silage at Northwind Farm, Walden, VT.

Corn silage: Silage made with whole chopped corn plants including the stalks.

Haylage: Silage made from hay crops such as grasses, clovers, and alfalfa fermented for storage.

Baleage: Type of silage that refers to hay in bale form and wrapped individually or in long tubes.

TYPES OF FERMENTED FEED STORAGE

UPRIGHT SILOS
Upright silos are made of concrete or steel, though occasionally you may see the remains of an old wooden or ceramic tile one. These were the first type of silage storage structure to catch on widely in Vermont. They preserve feed well and are space-efficient in small farmsteads, but laborious to fill with the forage crop and unload for feedout. Some farms still use these but few are being built today. They are more common in Quebec.

Example of upright silo, Maple Lane Farm, Cabot, VT. | Photo by Kelly Bogel Stokes.

WRAPPED BALES
Wrapped bales are the “marshmallows” you see stacked in farmyards and on the edges of fields, or in long tubes. Round or square, the bales contain a quarter to three quarters of a ton of “baleage” and are wrapped in oxygen-barrier plastic. These are favored by small to mid-sized farms for the ability to harvest and handle hay crops with a small crew and less equipment. This type of hay storage became popular in the 80’s and quickly took hold due to its versatility and the fact that it did not require vast amounts of indoor storage. On larger farms, the wrapped-bale method is too slow both at harvest and at feedout–a farm milking 500 cows might have to unwrap and feed as many as 60 bales every day.

Example of wrapped bales, Northwind Farm, Walden, VT.

BUNKER SILOS or “BUNKS”
Bunker silos are a common storage system: Most of the forage eaten by cattle in North America is finely chopped and stored in piles or concrete bunkers outdoors, covered in oxygen-barrier plastic weighed down by old tires. This method became popular as herds grew and larger acreages of crops needed to be harvested and transported to storage in a short time period. If you pass a farm when chopped hay or corn is being built into these piles, you will see large tractors driving up and down the piles for hours. They are compacting the air out of the crop for the best fermentation and longest storage life.

Packing corn silage bunk at Laggis Farm, East Hardwick, VT. | Photo by Johanna Laggis.

Haylage bunk at Laggis Farm, East Hardwick, VT.

AG-BAGS
Some farms use plastic “ag bags” to store chopped feeds as another storage option for smaller volumes of feed than would require a bunk, or for a specific crop that they would like to keep separate. These are long plastic bags that are filled with haylage or silage by a specialized piece of equipment. You can distinguish these from tubed baleage by their more squat and flat shape. 

Whatever the method of storage, a similar process occurs once the crop is safely packed in the silo, bale, bag, or bunker and protected from oxygen. Anaerobic bacteria such as Lactobacillus plantarum grow rapidly on the sugars in the plant tissue, producing organic acids as they multiply. The acidity of the stored crop increases and the storage life of the crop grows–think about the fridge life of a cucumber versus that of a pickle. This fermentation makes the nutrients in the crop more readily available to the animal when she eats it by essentially performing the first step in the ruminant digestive process outside the animal, and infuses the whole plant–from the lush leaves to the spiny seedheads and woody stems–with a succulent, sweet, vinegar-smelling aroma that makes the whole mixture more palatable to cattle and other ruminants.

✅ Advantages of Ensiled Feed ✅

Longer harvest windows and more weather flexibility
Storage stability
Increased palatability
Increased nutrient availability
Does not require dry storage

🌹Every rose has its thorn… a note on plastic. ♻️

As we have discussed, few farms utilize upright silos anymore, so the majority are using some form of plastic to form the oxygen barrier around their forages. Not only is this plastic quite expensive (around $7 per bale for net wrap and plastic), but it also amounts to an immense amount of plastic going into landfills because there is not currently a recycling program for the majority of ag plastic in Vermont. Ag bags and silage tarps can be recycled in some parts of the state, although not consistently, and bale wrap is not accepted by any solid waste management center at this time. A farm milking around 50 cows goes through about 2,500 pounds of non-recyclable plastic a year if they are feeding all wrapped bales…. That’s a lot of plastic in landfills! If this gets you as rankled as us, it’s definitely an issue CAE is interested in working on and we would love your support when the time comes. 

There is much more we could share about ensiled feed, but we will leave you here in hope that we have shed a little light on the big marshmallows you drive by on your way to work, or the piles of tires you’ve always wondered about. Fermented forages are a big part of dairy in our state, and though they are a bit less trendy than the pickles in your fridge, they certainly keep a lot of cows healthy and happy.