This time of year in the Willamette Valley, it is common to see big and small bales stacked in fields alongside the road. Some are square, some are round and some are wrapped in plastic that look like big marshmallows. What’s in them? Are they all the same? We are going to investigate these questions!


Hay is grass that has been cut, dried, baled and stored for animal feed. Hay is a very important component of a healthy diet for lots of different types of livestock including cattle, horses, goats and sheep.

What goes into harvesting dry hay?

1. Cut: The first step in harvesting dry hay is mowing. Mowing must be done on a sunny dry day. When a farmer cuts a field, the hay is left in windrows behind the tractor.

2. Ted: In order for the now cut hay to dry evenly, the next step is tedding. Since mowing lays the hay into compact windrows, it needs to be spread out to dry. The implement that is used for this is called a tedder and attaches to the back of a tractor with multiple baskets containing spokes that spin to fling the hay out evenly across the ground as the farmer drives over it. This can be done once or several times depending on the density of windrows in the field.

3. Rake: Once the hay is dry, it gets raked back into windrows so that it can be baled. This is done using a rake implement behind a tractor.

Field of hay bales in Philomath, Oregon

4. Bale: Next, the hay is scooped up and processed through a baler. There are several different sizes and shapes of bales that can be made depending on the animals it is being fed to, the feeding goals for the animal (ie, growth, maintenance, performance) and the number of animals being fed. Bales can be either round or square and range in size anywhere from 45 to 500lbs. Balers are very complex machines that can be adjusted to specific bale sizes, weight (density) and number of string or twine ties. Small square bales are more common for feeding horses, whose diets are usually more specific and monitored whereas the larger round bales are commonly used for feeding herds of cattle.

5. Haul/Store: The last step is hauling hay from the field to be stored in a location where it can be kept dry. Hay can be stored this way for a long time until it is needed by the farmer.

Haylage, very similar to hay, but with some important differences.

Affectionately resembling giant marshmallows, haylage is another forage option for livestock. However, there are a few differences in how it’s made that provide some important nutritional differences, that make it more appealing to some livestock producers.

The steps for making haylage are similar to that of making dry hay with a few exceptions. Grass that is cut for haylage is cut at an earlier stage of growth. Unlike hay, the haylage is not tedded to dry out and is instead left in the field for a much shorter time. This process enables farmers to preserve the moisture level of the grass.

So why is it wrapped?

The main difference between dry hay and haylage is that after it is baled, it is then wrapped in an air tight plastic wrap. The wrap creates an anaerobic environment. The lack of oxygen causes the pH to drop, preventing spoilage in spite of the high moisture levels. This process creates higher protein levels and is more digestible for livestock than dry hay.

Haylage is an ideal feed option when animals have high energy requirements (i.e. keeping themselves warm during the winter) or certain growth goals.


Straw is a byproduct from crops that are grown for seed. The left over stubble from cereal crops like barley, oats and wheat as well as grasses are commonly processed into straw. Straw is the stalk of the plant that remains after the seed has been combined. A combine cuts and threshes the grains of the plant using rotating blades, wheels, sieves and elevators manufactured in the combine. As the grain is collected inside the combine harvester, it separates the stalks and distributes them back onto the field. Once the remaining stalks in the field are dried, they are raked and baled just like hay and haylage.

Straw has several different uses. It is most commonly used for animal bedding or garden mulch. Straw from grass seed fields around the Willamette Valley are commonly exported overseas to be used for livestock feed in countries like Korea and Japan.

There you have it! There are many differences in forage options used for livestock. Farmers work to provide the best options for their animals to ensure that they are provided with a healthy and nutritious diet.