English Translation
More kids, more hands.
Google isn’t telling me much about the origin or the history or the meaning of this expression in German. It was apparently the title of a 1976 propaganda piece from the DDR, but I don’t know if that’s where this comes from, or if that piece simply made use of an existing expression.
My guess is that it means that a family that has a lot of kids is better capable of running a household, or a family farm maybe? Using the kids as free labour? I don’t think there’s an equivalent expression in English if so, and “more kids, more hands” certainly doesn’t say much.