A cow or a donkey or anything that works and eats may be assessed at half profit. [In] a place where they are accustomed to divide the offspring immediately, they divide [them]; [in] a place where they are accustomed to raise [them], they must raise [them]. Rabban Shimon ben Gamliel says: A calf may be assessed with its mother, and a foal with its mother. One may in-crease the rent of his field, and he need not fear that it is interest.