The science of baling hay

We all see bales of hay strewn about farmland as we drive throughout Wisconsin, and we'll see it being fed to the animals, mostly to cattle. We happened across a field that was being harvested while in Pine River, Lincoln County, and took a bunch of photos. In trying to present these photos to you, we had to research what we were going to talk about and discovered, yet again, that nothing in life is simple, everything is complex, and there is a real science involved in baling hay. We'll introduce you to just a smidgen of that science.

June 29, 2006, updated with some photos of wrapping the hay, July 19, 2010

Well, we're going to get in way over our heads on this story. We were driving on Deer Run Avenue in the town of Pine River, Lincoln County, the other day, and became fascinated with a guy out there harvesting and baling hay. He appeared to be largely done, and had those round bales all over the place. The photography we have is good, but it fails to express the breadth of area occupied by the bales. Suffice to say, the area was big, at least to those of us who are rookies at this profession.


Our count on this photo is 38 bales just in this one small sector.


Just so we are all talking about the same thing, this is what's called a "large round bale." You might laugh, but there are several different ways to bale hay, in terms of shapes and sizes. You can have small square bales, which need to be "square shouldered" so they hold their shape. "Banana" bales and "almost broken" bales are not so good. Small bales are easier to move, and some animals prefer them. Larger bales are lower cost but usually have to be delivered to the customer.

This brings us to our point in this story. As we started searching around for information about baling hay, we learned in less than a few minutes there is a real science to this, and a lot of it.

We'll not go into the subject in any kind of depth. We simply want to expose you to some of the issues farmers must confront when baling hay. The next time you see the bales all lined up, you'll have something to think about.

First of all, we're not talking about hay or grass, we're talking about forage. Forage is a word which is used to describe bulky foods such as hay or grass.


These are llama, and a pig off to the left, gathered around their forage at Joe and Cindy Cano's Iron Corral Exotic Farm in Viola, Vernon County.

This food is used for a variety of animals. In Wisconsin, the common ones are cattle, bison, deer and elk, goats, horses, swine, and yes, llamas.

In the context of our discussion, we are talking about "ruminant animals." These are animals that chew the cud regurgitated from their rumen, or their stomach, sometimes called their first stomach.


This diagram, presented by the University of Kentucky, shows a ruminant's digestive track. The ruminant, let's say a cow, eats the forage. The forage passes through its esophagus to the rumen, which scientists see as a large fermentation vat, also called the "paunch." There is not much oxygen in there, but there are a lot of gasses. The gasses in the rumen cause the bolus or the chewed food to regurgitate, or pass back up the esophagus into the mouth. The ruminant then rechews that bolus, invigorating it with more saliva, and passes it back to the rumen, where the process continues. The rumen hosts many microorganisms which eventually digest the food making fatty acids, protein and vitamins. Eventually everything passes into the abomasum which is the true stomach and passes into the large intestine for water absorption and the small intestine for the final digestion of proteins, carbohydrates, and fats.


Alfalfa field. Presented by the Government of Alberta, Canada.

There are multiple species of grasses that make good forage, including rye-grass, orchard-grass, tall fescue, corn, sorghum, sudangrass, and alfalfa.


Sorghum field. Presented by Kansas State University.

Some are cool season and others are warm season grasses. This is a serious business. Wisconsin has over 4 million acres of hay and grass, also known as silage. Eighty five percent of this production is fed to livestock, so the return on investment in silage to these farmers occurs when they sell their livestock or livestock products. But hay and silage have also become a cash crop, which means that farmers can sell it to those livestock farmers who cannot or do not want to grow it themselves.

Most of the forage in Wisconsin is from legumes (planted by seed), including alfalfa, birdsfoot trefoil and red clover, and grasses (grow wild), including Kentucky bluegrass, orchard-grass, reed canary-grass, ryergrass, tall fescue and a few others.

The important point we want to emphasize by telling you about the ruminants and silage is that there is a soil-plant-animal biological system involved here. This is not simply a matter of growing hay or grass and dumping it infront your livestock. We are talking about grassland agriculture and livestock management. Managing grassland agriculture directly impacts managing livestock and the land.

Managing grasslands often has a lot to do with the trade-offs between yield and quality. Often, quality improves as yield goes down, but reduced yield means reduced profitability. There is a great deal of science involved in these equations.

We do not know exactly what forage our farmer in Pine River was harvesting, but we think it was alfalfa so we'll use it as an example. Alfalfa and alfalfa-grass mixtures are grown for hay on over 3 million acres in Wisconsin. It is the foundation for feeding programs for dairy cattle, replacement heifers, beef cattle, sheep and horses.

Let's take a look at the equipment our farmer was using. As an aside, we also don't know if this is the owner of this farm, or if he was subcontracted to do this job for the owner. The economics of farming today requires investment in capital assets such as the equipment that produce a high rate of return on investment. Sometimes the kind of machinery we are about to show you is used only a little bit each year on each farm. In that case, it might be better to hire someone, usually referred to as a custom operator, to do the work for you.


At the point we arrived on the scene, he has used machinery to cut the crop known as a "mower conditioner" and he has baled almost all of it. In the center of this photo, you can see the cut crop lying there waiting to be baled. The "clean" areas around it are the areas that have already been mowed and conditioned, picked up and baled. Above center, it looks like there is some (tall and very green) yet to be mowed and conditioned.

As a general rule of thumb, moisture is the enemy of high quality forage. That is especially true in Wisconsin, where humidity can be high. Furthermore, rain that occurs between the time the forage is cut and harvested causes yield and quality losses that reduce the value of the crop on the market. The rain removes cell solubles out of the crop, solubles that are very digestible by animals. Leaching of soluble carbohydrates reduces the forage's value, because reduced carbs mean reduced bacteria for the fermentation process that occurs in the rumen. Reduced fermentation means less regurgitation etc.

So lots of daily decisions and consultations with the weather radar are needed to decide when to cut the crop.

But farmers don't just cut the crop. They "condition" it through a system called "mower conditioning," and they dry it in the field before baling it.

What do we mean by mower conditioning? As the crop is cut, it rubs against itself and against a specially designed mower hood, which "scuffs" the entire stem. That allows moisture to escape faster. The faster you dry the forage, the better the quality. The sun is the primary means for drying in the field. You want the cut forage to dry rapidly so it is not exposed to the possibilities of unwanted additional moisture any longer than necessary.

Swath width is another very important adjustment when mower-conditioning. Creating a wide swath will increase the potential for more rapid drying of the forage.


Here you see our farmer with his harvesting equipment. He is dragging a Claas Rollant harvester with his tractor. Basically, the harvester picks up the cut forage and bales it, then simply drops the baled forage out the back.

Here are some photos of that process.


This is a Claas Rollant 160 producing the bales. Photo credit: Claas of America, Inc.

If you look back at our farmer and his Rollant, the forage is picked up at the front of the harvester.


Pick-up mechanism of the Claas Rollant 160. Photo credit: Claas of American, Inc.

Strong drives in front of the machine "rake" up the forage. Extra wide swaths are used. If you look at the area surrounding the Rollant, you can see that the area is cleanly raked, remarkably so if you ever raked leaves at the house!


Packer tines on the feed rake are located behind the pick-up. These packer tines feed the crop into the baling chamber. The throughput is fairly fast. Our farmer was moving along at a nice, even clip. (Photo credit: Claas of America, Inc.)


Here you can see the rollers used to form the bale inside the baling chamber. (Photo credit: Claas of America, Inc.). The bale is wrapped with twine or netting or both after it is rolled, inside the chamber. The operator is then notified by a buzzer that the bale is ready for discharge, the tailgate pulls the bale out of the chamber and it rolls back and out, after which the tailgate closes and the process resumes.


Here is a close-up of a completed bale. The netting employed is obvious; we cannot see twine, but it might be in there as well. It is important that each bale be tightly wound and packed so it does not fall apart when moved.

There are many things to consider in this process and the post-baling process.


Once the forage is baled, there are all kinds of actions that might occur and issues to be confronted. Here you see a fairly primitive means of moving the bales. Two bales are loaded on a simple wagon, and there is a loader sitting there waiting to upload more.

Let's say he is going to deliver these bales to a customer. He'll have to determine the weight of each bale in order to assign a price, and to determine maximum loading on the transportation means. He also needs to know the weight in order to determine and report crop yield, adjust crop management practices, and determine his storage requirements. Most farmers do not have scales for this purpose, so experts have developed a way to estimate weights, too elaborate a mathematical system to discuss here.

You will often see bales wrapped in plastic, usually a white plastic. This is more expensive, but bale wrapping does produce good, reliable results. We have seen recommendations that also suggest covering bales; the best method is to stack three bales in a triangular formation. Doing it this way means you have to add preservatives.

We have not discussed how to present the forage to the animal. A horse will typically consume 2.0 to 2.5 percent of its body weight per day in forage dry matter. Sounds easy enough. But the darn horses will trample some of the forage and other forage is wasted, something like the kids not eating their whole meal at the table.


In this photo, which we took last winter near Viola in Vernon County, while driving on Hwy 131, you see three horses. In the upper left corner, you see a blue truck dragging two round bales of forage. We're not sure what he'll do with it, but it looks like he intends to just leave it there for the horses.

Horses demand a different quality of forage than do cattle. Horses want their forage dust-free and mold-free. Mold especially will cause irritation in their respiratory tracts and colic in their digestive tracts. Horses do not require high crude protein content, though that varies with horse type and age. As a rule of thumb, for horses, mold-free hay is more important than high-nutrient hay.

Horses generally like an alfalfa-timothy mixture. They really like a sweet smelling mixture. They don't like weeds and junk in their forage. They prefer soft forage, because their mouth, lips and tongue are very soft and sensitive. If you watch them, they'll sort through their forage and leave coarse stems to the side. Baling hay for horses usually requires the operator pay very keen attention to the weather, and shoot for the largest low-precipitation window he or she can get.

Usually a stable can handle only 50 lb. bales, usually in the vicinity of a 36-38 inch bales. This often means the owners will prefer small square bales. Such bales are handled many times, so they need to be square shouldered and hold their shape.

We could go on and on and never stop, there is so much involved in this process, so much to learn. We hope we have given you a flavor for that, should you wish to research the subject more, especially to study what you might see as you drive around the rural parts of the state.

July 19, 2011

Driving through the southeast corner of Lincoln County, on CH X or County Line Road separating it from Marathon County, I ran across an operation where they were wrapping the rolls of hay. This was quite an enterprise.


You can see this organization has already wrapped a lot of hay, but still has a way to go. I am not sure whether they are doing other people’s hay, or just their own.

I have learned that before wrapping the hay rolls, you must be certain they are dry. White wrapping is most often used. It is readily available, and is better than a dark color while the hay sits wrapped in the sun. Some farmers say even with the white wrapping the hay gets pretty darn hot in there. Some leave the ends open for some ventilation, I presume, while others close the ends. I believe these people were leaving the ends open. They are usually opened for feed in winter and early spring. My photos were taken on July 3. In retrospect, I wish I would have gotten right into the middle of the activity, but I did not want to interrupt so had to shoot from the roadside. I’m going to have to do a little ‘educated guessing here.”


I did not notice this when I was there, but the arrow to the right points to a pickup truck. He has a Featherlite trailer hitch attached to the bed of his truck. I believe he has a ong flatbed trailer attached to that, which he used to deliver his rolls of hay. The guy working to wrap the hay picks up the rolls from the flatbed and puts them onto the machine that will wrap them.


This is a closer look at the Featherlite hitch. In looking at the previous photo, you can see that he has several unwrapped rolls behind him.


Here you see the machine preparing to pick up one of the rolls of hay off the flatbed.


This is a larger view of that photo. To the left, he is picking one up off the flatbed. To the right one roll is going through the wrapper and another is waiting to go. This is a hup-to-three operation.


He’s picked up the roll off the flatbed, and is now preparing to drop it onto the wrapping machine. You can see that one is getting wrapped.

You really had to be there to watch the speed at which this operation proceeds. Loved it!