It is a question I get asked a lot. I have even gotten it a PAC event.
Yes, it comes in different forms, but the root is the same: what does the perfect cattle feeding pen look like?
And my answer is… it depends, followed by a whole slew of questions. Sorry to disappoint, but I do not have any silver bullets here.
While there may not be a magic formula for the perfect pen, what I will share is the thought process I try to work through with my customers to help them optimize pen design given their unique constraints.
The conversation usually starts here. What is our desired target for bunk space and pen space?
These two factors will ultimately drive our pen dimensions.
Are we feeding yearlings or starting bawling calves? How many time per day are we feeding?
Are we finishing cattle or just backgrounding? What is our average annual rainfall for this location?
Let’s talk about bunk space first.
There continues to be interest in finding the lower end of the range and that appears to be somewhere between 5.5 to 7.0 inches per head, but the old rule of 1 foot per head is still quite common.
At the end of the day, bunk space and many of the other factors that influence pen design end up being a bell-shaped curve. That holds true with pen space too.
For me, pen space correlates closely to rainfall.
In eastern Nebraska, that number is often 350 to 400 square feet per head.
In northeast Colorado, 200 to 250 square feet might be a better place to start the conversation and the folks down in the Texas Panhandle are lower yet.
The real question about pen space is not the total, rather the usable pen space especially during inclement weather. And that leads us to the next topic.
The slope of our perfect pen also tends to track with precipitation, with more slope desirable in wetter areas.
Often times, we are restricted by what the natural topography of a piece of property gives us.
It is almost always cheaper to create slope on a flat piece of ground than to eliminate it on something greater than optimal.
The lower end of this curve usually starts around 2% and tends to peak about 3.5% and end around 5%.
Don’t get me wrong, there are plenty of pens with slopes 6, 8, even 10% that are full of cattle right now, but when it comes to designed pens, we are usually shooting for something less.
There are typically two thoughts when it comes to drainage. One is to get the water out the back into some type of stormwater conveyance.
The other is to put a flow line parallel to the bunk running through the pen. This second option is certainly more common in dryer climates.
Our grading plan and pen slope is definitely influenced by our thoughts on manure management and the runoff control structures – ditches, basins, ponds associated with our perfect pen.
From here the conversation can head in a number of different directions, but there are a few topics that need to be addressed to get things dialed in.
One is pen surface. Most of our feedyards are soil pens with a concrete apron adjacent to the bunk.
The width of that apron is debatable but commonly ranges from 10 to 30 feet.
However, there is considerable interest in paving more or even all of the pen surface especially with roller compacted concrete (RCC). T
he next topic is water tanks. What brand? What size? How many? In the fence line or in the middle of the pen? Overflow waterers or electric heat?
The opinions here are as diverse as the cattle that are going to drink out of them.
One thing that I have had lots of discussion about lately is multiple access points to water and designing the underground water supply system in a fashion that some of the tanks are for year-round use while others may be for summer use only.
The third conversation point relates to getting in and out of the perfect pen.
Do we move cattle in and out of the pen using a rear drover’s alley, or do we break the bunk and take cattle out the top side of the pen. What about equipment?
Drover’s alleys are more prevalent in drier climates, but sometimes both options are desirable for flexibility or separation of cattle and vehicle traffic.
Somewhere along the way, there are a couple of other things that tend to pop up that I think are worth mentioning.
Many of our customers have a desired pen orientation. Do we want the bunks running east/west or north/south?
Typically, we prefer south facing pens because they tend to dry out quicker, but we are not always blessed with a site where that makes sense for other reasons.
It may seem obvious, but the number of cattle per pen is also quite variable. Are we custom feeding or feeding our own cattle?
I tend to see fewer different pen sizes in yards feeding their own cattle, but in either case, correlating the size of the pen to the number of head arriving on a truck or trucks is often a driving factor here.
Another point of consideration is how important are shared feed alleys?
Double bunk lines with a single wider road are generally preferrable, but sometimes this goal conflicts with our grading plan for the right pen slopes.
There is no doubt in my mind that the question about the perfect pen will continue to come up.
And as you can see, the answer is not so simple. However, there is beauty in the complexity.
Some days feedlot design feels like much more of an art than a science.
The reality is that no matter the situation, there are a variety of variables we want to evaluate and balance to build the best pen for you and your business.
Until next time, God Bless.
Jacob Mayer is a Project Engineer for Settje Agri-Services & Engineering (www. settje.com) located near Raymond, NE. He is a licensed Professional Engineer and has a B.S. in Agricultural Engineering from Iowa State University and M.S. in Biological Engineering from Mississippi State University. He resides in Saunders County, Nebraska, with his family. He does not wear a pocket protector and does not know how to use a slide rule.
Get all Doc Talk episodes straight to your email inbox!
