Chickens tend to be messy eaters. If you feed them in round open pans, you are almost sure to come back later and have uneaten feed scattered all around the pan. Depending on the number of birds you have and how much feed you put out for them, a good portion of this food could get eaten throughout the day. However, if more than a little bit of their daily ration is spilled out on the ground and becomes wet, you have opened up the possibility for mold to form. Mold introduces all sorts of bad juju for your birds.
There are several ways to reduce spilled rations and I use two that I feel do a pretty adequate job for my setup. First, since my birds free range quite a bit, I reduce the amount of dry feed that the birds have access during the day. This is an everchanging process due greatly to seasonal changes. I tend to feed the birds more dry feed in the winter due to a lack of forage. I leave them less feed during the summer as they have a large area to get fresh greens, insects, and the odd lizard. When I first started reducing rations, I did it on a weekend that I would be around so that I could monitor how well the feed was consumed. If it seemed that they looked like they would run out, I added more. If it looked like they left more on the ground, I reduced the amount I fed. This is not an exact science, but with a little bit of observation you can figure it out.
The second thing that I did was to construct a PVC feeder with holes where the chickens could get to their feed, but not get their feet in to scratch. Mine is constructed out of 3” PVC and consists of straight pipe, 3 caps, a 45 degree elbow, and a sanitary Tee. A word to the budget minded person here is that you should use drainage PVC instead of pressure as it is much cheaper. From top to bottom, my feeder is roughly 5 feet tall. This includes a roughly 3-foot vertical pipe connected to a 45-degree elbow that is then attached to another foot and a half of straight pipe. A sanitary drain Tee is then attached, with a capped one foot section out of each side. The horizontal pieces have holes bored in them with a whole saw. The lower pieces are also screwed together instead of glued to allow disassembly for easier cleaning. I have since replaced them with longer pipes with wide slots in them rather than holes to allow more chickens to feed.
This gravity feed system allows multiple chickens to eat out of the feeder at once, reduces waste, and also allows me to fill the feeder with several days of feed at one time. This reduces the time I spend tending to chickens slightly each day. The all vertical pipe is topped with one of the PVC caps and that keeps water from getting into the top. The angle at the bottom allows the base to be offset from the side of my run so that it can be protected from weather. Overall it is a good system and works well for my flock size. With the chicks that I am getting this weekend, I do feel that I will soon have to augment this feeding system with an additional feeder or two.