For my experience i know that the term "кормилец" is used not only for men, but for animals and inanimate objects. For example, my grandmother called her cow with this word, because it was really hard to live in the village without a cow. I also heard that a man called his truck buy this word, because it was the only way to get money for him buy transporting wood. And yes, we don't use the word "поилица"