PROBLEMS IN ANIMAL NUTRITION. 509 



There were killed in the wholesale slaughtering- and packing houses 

 of the United States in 1900 five and one-half million cattle, nine mil- 

 lion sheep, and thirty and one-half million swine, or a total of forty- 

 five million animals, estimated to be worth $(')8;'>,000,000. The value 

 of animals slaughtered on farms was estimated at $100,000,000, mak- 

 ing a total value of $878,000,000. Adding to this the value of our 

 dairy products, about $433,000,000, and that of the poultry and egg 

 production, about $28-2. 000,000, we have a total of about $1,588,000,000 

 for the yearly value of the ()ut})ut of animal foods. 



For both of the purposes just named, the animal utilizes the 

 energy originally derived fi'om solar radiation and stored up in 

 vegetable products by the synthetic action of the chlorophyll. The 

 point of economic importance in this connection is that these enor- 

 mous aggregates represent to a considerable extent a utilization of 

 the potential energy of inedible products which would otherwise 

 be a waste so far as food value is concerned and largely so as a 

 source of power. This is true on the one hand of the leaves, stems, 

 husks, pods, etc., of our various farm crops — the so-called coarse 

 fodders — and on the other, of those manufacturing by-products 

 which accunndate in the preparation of grains and other raw ma- 

 terials for human consumption. By feeding these products to our 

 domestic animals, we utilize for feeding man or performing his 

 work a portion of their stored-up energy, which would otherwise be 

 practically an entire waste. Of course surplus edible products are 

 also utilized in stock feeding and in this country very largely so. 

 This, however, can only be regarded as a temporary phase of our 

 agriculture. AVhile, on the fertile soil of the corn belt, it is often 

 found more profitable to convert corn into beef or pork than to 

 market it directly, as the density of population and the demand for 

 l)readstuifs increase, the stock feeder will be more and more con- 

 strained to the use of the cheaper by-product feeds in place of grain. 

 From the economic point of view, then, it is highly important that 

 that portion of our national wealth represented by these inedible 

 j)ro(lucts should l)e utilized to the best advantage, yielding a greater 

 aggregate profit to the producer and a more liberal supply of animal 

 food to the consumer. 



Time jirevents more than a mere reference to the important rela- 

 tions which subsist betwee-^ aninuil husbandry and the j)reservation 

 of soil fertility. While we no longer regard the farm aninuil as a 

 mere manure machine, still the nuiintenance of the fertility of the 

 farm is an important element in determining the jirofits of stock 

 raising, and from this point of view, as well as from that of the more 

 complete utilization of solar energy, those forms of agricultui'e are 

 to be preferred, other things In-iiig ('([ual, which maintain a due bal- 

 ance between the production of crops and of aninuils. 

 20915— No. 6—07 m 2 



