It is well to remember, in feeding livestock, that not only do different species of animal require different feeds, but also that growing animals usually require rations different than fattening or mature animals. A good general rule is that grow·· ing rations should contain a higher percentage of protein than fattening rations. Another wise rule is that in feeding an animal, be it sheep, hog or steer, begin with the proper feeding of its mother before and during pregnancy. With these simple rules in mind, we may briefly consider some of the aspects of the problems of feeding livestock.