I'm doing pretty much the same thing. Converting an area of lawn out back to poultry pasture. This lawn area was mostly sterile junk....crabgrass, fescue and maybe remnants of bluegrass or rye. It will be a series of raised beds, sporting alternating strips of seasonal fodder. Cover crops like oats and winter peas, rape (same plant they grow canola from), forage turnips, tillage radishes, beets, etc. Perhaps some Korean lespedeza. If you want some fast, quick and dirty high stuff for them as shade and hide under, scatter in some sudan grass seed. In addition to green stuff for them to eat, many of them will attract insects of various kinds. Some, like sweet corn, field corn, sunflowers, and that sudan grass, in addition to being tall protective playpens, are also heavy feeders of nitrogen and phosphorous, which the chicken manure is high in and which tend to accumulate and overcook your ground if you are not careful. So these plants feed on the Nitrogen at least to tie it up.
But all of these plants have to be protected until such time as they are either large enough to not be affected or enough of them to overwhelm the number birds you have. So much that they can't keep up. I going to use some 28" high poultry netting to ward them off during the establishment period. Initially, it may have to be hot to train them not to mess with it, but for the most part, it won't be left hot, which eliminates the maintenance issue.
Chicken and other livestock manures are good, to a point, but over time, you can get too much of a good thing. All the salts, all the minerals like phosphorous, calcium, etc. keep building. The best way to filter those is to use plants that are heavy feeders, then remove the plants.