Complex sentence: The eastern steppe provinces are informally known as the "horse provinces" because of their suitability for horse breeding, while the northern mountain provinces are considered "cow provinces," though horses are reared there as well.
Split into simpler sentences: The eastern steppe provinces are informally known as the "horse provinces" because of their suitability for horse breeding. The northern mountain provinces are considered "cow provinces," though horses are reared there as well.