4 HUMAN FOOD PRODUCTION 



example, as corn and potatoes, while the remaining sixty per cent 

 of the energy is in the stalk, leaf, cob, and straw. If we add 

 to this amount the meadow hay and permanent pastures, it seems 

 highly probable that fully seventy-five per cent of the food energy 

 captured in this country, each growing season, is in such form 

 that it is practically useless as food to man until converted by 

 soHije animal into the form of flesh, milk, or eggs. Plants get 

 their energy from the sun and their substance from the soil and 

 air, while animals get both substance and energy from plants 

 (or other animals). Man is no exception. 



Utilization of Waste Forage. — One important reason why 

 livestock is, and should be, kept on most farms, rather than 

 devoting them exclusively to the growing of grain, potatoes and 

 roots of which man can eat only a part, is because of the power 

 of animals to consume and work over a great quantity of com- 

 mon pasture grass, low land hay, corn stover, and some straw. 

 They consume the coarser by-products formed in the making of 

 human food, for example, bran and shorts, or in the making of 

 some other commercial article. Where linseed oil is made for 

 painting purposes there is left linseed oil meal, and where cot- 

 tonseed oil is made there is left cottonseed meal. Both are 

 highly nutritious as stock feed. These substances may be fed 

 to produce beef, milk (Fig. 1), mutton, or, to some extent, 

 pork. The hog has wonderful powers of flesh formation, in 

 fact, will produce more flesh for the quantity of feed consumed 

 than any other kno^vn animal, but his power to consume coarse 

 stuff is limited. The sheep is a highly valuable animal and 

 should be kept in greater numbers " than at present, but its 

 peculiarities prevent it being kept in such numbers as adequately 

 to consume any large jDortion of the coarse feeds grown on 

 American farms. So, at least for the present and probably 

 for many years to come, the consumption and conversion of 

 the bulk of the coarse feeds of our farms must be done mostly 

 by cattle. 



The Covi' vs. the Steer. — As a food producer, or, more 

 strictly speaking, energy transformer and conserveor, the cow, 

 according to Haecker of Minnesota, returns in her product 



