The bigger the better. Mine are about 30ft wide and around 400 ft long. I wish they were a little wider sometimes, but if they are too wide it can be a pain bringing in barn sour cattle by yourself at times. I would have built them bigger but was limited on the space I could use. If you go wider maybe make them funneled at the front to make it easier to get the cattle in.
JEEZ thats is not what I was hoping to hear, this is just where the calves will be at night and then they will be put back in the cooler, and they still get excersised everyday, so I dont think I need 30x400 :'(
30x40 with 12 x 20 loafing shed for shelter is what I use. But then again I don't run them in a cooler during the day so they might need a little more room since they will have all that hair.
<alien>
i have 3 16 month old calves out on a 90x50 lot and they can come in an out of the barn as they please, its plenty of room , just the right size, and easy to get barn sour ones back in