There are special hens for soup? I think over here they are bred for two types: fast growing with a lot of muscle, for the meat, and those bred for producing lots of eggs. Those build muscle slower (and less) and get stringy, tough meat, and will get used in soups, as cooking softens it.
Which also means that they basically kill the male chicks right after hatching, a practice they are finally in the process of stopping, by detecting them early during incubation. (Another method is raising and slaughtering them for meat anyway, by making the eggs slightly more expensive)
