is not the place here to go deeper into this problem which has long been a subject for thorough research and experiments. In fact, more attention has been paid to the feeding of cattle than to the proper nourishment of human beings, and much of what we know about the latter has been deducted from experience and study on the dairy farm, and from laboratory work along that line. In the chapter on "Milk as a Food" we are taking up food values, etc., in relation to the feeding of children and men. Suffice it here to say that the same fundamental principles apply to the feeding of calves and cattle for the production of milk and beef. And we wish to emphasize the fact that, with due consideration to the proper proportion between the various groups of nutrients, it is much more important that the food is succulent, appetizing and easily digestible than that the ration shall be accurately balanced.
This fact, long well known to practical breeders and dairymen, has recently been confirmed by Dr. E. V. McCullom to whose experiments further reference is made in the chapter on milk as a food for children. He shows that there is a very great difference in the quality of Protein and Fat from various sources and that there is "Something Unknown" in butter-fat, for instance, which is absent in most other fats and which is vital for the growth of the child as well as for the proper nourishment of man. This unknown but essential substance is also found, in small quantities, in the leaves of certain plants, as in alfalfa, while it is absent in the grain of the cereals.
In modern dairy farming alfalfa is considered an indispensable source for protein, and corn-ensilage or beets for carbohydrates, while bran, cottonseed meal or oil
