Chicken tractor engineering 101

Chickens in portable pen

Chickens enjoying a sunny day

Rotating chickens onto new pasture frequently is good for several reasons. First, when chickens are confined to a specific area rather than free-roaming, they pretty quickly dig up all the grass, as they scratch for bugs and take dust baths. They like to eat fresh greens, though, so they appreciate being let out on new green areas so they can browse. With a portable chicken pen, also called a chicken tractor or chicken ark, the chickens can have new green area frequently and they can also contribute fertility to different areas of the farm.

Once they are large enough to live outside safely, we house our broiler chickens in portable pens so they can live on pasture, eat grass and bugs, and get plenty of sunshine. You will find many, many web pages on chicken tractor construction. Even with all those posts, it’s still tricky trying to decide how to build a chicken tractor yourself. Some tractors seem either too large to move without a tractor or too small to give the chickens room to roam. Many are designed to use PVC pipes, which we do not ever buy due to the toxins released during their manufacture. For us, we want the tractor to be constructed as cheaply as possible, while still lasting for many growing seasons with little or no maintenance. It also needs to provide adequate space for the birds in addition to protecting them from the elements and from predators. Most posts do not actually provide much detail about construction considerations, though, and most are built for laying hens rather than broiler chickens, so the requirements are slightly different. For broilers there are no nest boxes, or perches, for example.

I do not claim to be an authority on chicken tractors, but we have learned some things that worked and didn’t work in the domain of portable chicken housing, so here I offer a short list of design considerations to keep in mind for building a portable pen for broiler chickens.

  1. Keep it light, but not too light. This is the trickiest design criteria, in my mind. If you want to be able to move your chicken pen by hand, rather than needing a tractor to pull it, it should be as light as possible, but not so light that it will tip over in heavy wind. One thing we’ve learned in our few years of farming is this: never underestimate the forces of nature. I see many lightweight PVC or hoop-house style chicken arks that I know would not withstand our worst New England wind gusts, and a bear could easily push them right over and snatch out the yummy chickens within. We build the structure of our houses from wood rather than PVC, using 2×2 beams instead of 2×4 wherever possible to reduce the weight. But the bottom rails are 2x4s so that the structure is bottom-heavy. The height of the pen also factors into the total weight, so you don’t want it unnecessarily tall. We think 24″ is too short for the birds to be comfortable, but 36″ high is unnecessary for meat birds, since they don’t perch. A 36″ wall makes it hard to lift the 3-gallon waterer over the side and into the pen. We find that 28″ is a good target height.

    Chicken tractor side view

    28 inches tall: gives the birds plenty of head space, without being too tall for humans to reach in

  2. Plan for human as well as chicken access. You’ll need some portion of the pen to open up to lift out the food and water containers. Then on slaughter day, you’ll need to be able to get the chickens out of the pen. For both of these functions, we build our pens with a hinged lid to allow for easy human access. A key detail is to design in a kick-stand to prop the lid open while we refill their food and water. You could also just let the lid flop backwards when working with the feeders, but over time that would stress the hinges, and the chickens are more likely to jump out if the roof is totally opened up.

    Propped up lid on chicken tractor

    Kick-stand props up chicken tractor lid

  3. Predators are smart, and they have all night Our property abuts a conservation forest, so bears, coyotes, foxes, raccoons, and weasels make frequent visits to test the security precautions we’ve built around our animals. On our chicken tractors, we apply an inner layer of 2″ chicken wire, as well as an outer cover of 1″ wire. When a raccoon spends time plucking the first layer of wire out of its staples, it is confronted with the 1″ wire. The alternation also means there’s not an easily-expandable opening for a raccoon to reach through and pull a body-part out through the mesh. The wire is wrapped slightly around the bottom edge of the pen, so that it sticks out into the interior just slightly, along the ground. Predators trying to dig under the pen come to the wire pricking them before they hit open dirt. Also, the lid closes with a covered hook-and-eye so that raccoons can’t open the lid.

    Predator proofing the chicken tractor

    Hasp on chicken-tractor lid

  4. Build for strength Although the chicken tractor’s main function is to provide cover for the chickens, it is more than a portable tarp on wheels. All that pulling and tugging will create stress on the frame. Someone will forget that the roof is just made of chicken wire and set the feeder up there. We reinforce all corners with plywood triangles, and the lid has multiple cross-pieces for stability and strength.

    reinforced corners in chicken tractor

    reinforced corners in chicken tractor

  5. How to pull it? I like the chicken tractors that have gurney-style handles built right in, but we haven’t built ours like that. Our first chicken tractor had a rope attached at each end, but rope is probablematic. I would pull with all my might and the tractor didn’t move, the rope just stretched with me. Because of that, we’ve switched to chain pulls that are covered with an old piece of hose to make the grip more comfortable. We install eyelets at both ends of the pen, so the chain can be clipped to either end to move the pen in either direction. Be careful not to make the chain too long, because you need to get the end of the pen lifted up off the ground slightly to overcome friction and slide it forward.
pull handle on chicken tractor

pull handle on chicken tractor

If you’ve built a portable chicken pen, please add your insights into the comments. We hope you find these tips helpful.

Be Sociable, Share!
Posted in Uncategorized.

Leave a Reply

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