Ordinances of that type are usually county by county or township by township. If your county has website, a link might be there. Or you may try call planning and zoning(if they don't handle it they can usually direct you to who does). It is possible there are no polices about how many chickens outside city limits (short of some giant 100s or 1000s of birds farm regulations) or there may well be regs for the whole county which differ by where you live or the size of your property. Try to see if the county official you speak to can direct you to something in writing (it wouldn't be the first time an employee really didn't know what the rules really were). There may also be some state AG regulations you need to know but most of the time that isn't going to be an issue for 2 dozen chickens.