The best substitue would be to use cottage cheese (the taste is similar). Drain the liquid from the cottage by placing it on top of cheesecloth that is placed over a bow.
a substitute for farmer cheese is goat cheese made from goat milk.... don't ask me my lil sisters dad has a farm and made it and i was just listening to her wonderful stories now dont u think im...
Goat cheese, ricotta, curdled cream (Devon Cream), depending on what you are using it for. If you are using it for a salad you can go with crumbled blue or Gorgonzola also.
Quoth Wikipedia:
"Farmer cheese (also farmer's cheese or farmers' cheese) is a simple cheese often used for fillings in blintzes and other foods. Farmer cheese is made by pressing most of the...