Rabbits shed their old coat between 4 and 6 weeks from birth. And while in this phase, they should not be mated but fed with extra food, since this is required for good health and the production of a new coat. This calls for production ration which rich with calcium and Vitamin C and cabbage is endowed with them adequately.
Calcium is required in large amounts during infancy and early development when the skeleton is developing. Also required in considerable amounts in breast feeding.