Is there a single kind of feed that I can give both my roosters and hens? We can't afford to buy 2 or 3 kinds of feed and wonder if there's one thing that'll cover it all.
Yes there is. It may be called Flock Raiser, or Multi Feed, or All Flock but the important details are any feed containing 16% to 20% protein and 1% or less Calcium. It is advisable to provide a source of calcium for any layers in the form of Oyster Shell or calcium carbonate separately from the main feed. Calcium supplements are very cheap and last a long time.
Not sure where you are or what is available for you but you're not likely to stop them from eating each other's food anyway. There are techniques but I'll leave those to the commercial breeding operations. There are two significant differences in the different feeds, calcium and protein. The other nutrients are pretty close to the same. The calcium should be around 1% or around 4%, it will vary some but in those ballparks. You want one that is closer to 1% than 4%. That info is in the analysis on the label. The protein can vary a lot, typically from 15% to 24% but I'm sure there are others even more extreme available. You can get different opinions as to which is best but I prefer somewhere in Shadrach's range between 16 to 20% protein. Pick whichever you are happy with or what is available. Then offer a calcium supplement on the side. Those that need the extra calcium for egg shells seem to know to eat it while the ones that don't need it don;t eat enough to harm themselves.