328 THE ESSENTIALS OF AGRICULTURE 



The common materials that are rich in minerals are milk, 

 meat-meal, tankage, alfalfa, clover, rape, blue grass, bran, wood 

 ashes, bone meal, and limestone. 



426. A balanced ration. Animals require protein, carbohy- 

 drates, and ash, in varying amounts and proportions. A balanced 

 ration has the proper proportion of protein, carbohydrates, and 

 ash to serve the particular needs of the animal. The question 

 is constantly presenting itself as to the source of proteins to 

 balance the cereals and hays, which contain too large a propor- 

 tion of carbohydrates to meet the needs of animals that are 

 growing, working, or producing meat, milk, eggs, or wool. 

 Skim milk, meat-meal, or tankage from the packing houses 

 are familiar forms of animal protein ; and cottonseed meal, 

 linseed-oil meal, bran, middlings, alfalfa hay, clover hay, 

 peanuts, rape, soy beans, and cowpeas are common sources 

 of vegetable protein. The locality in which one lives usually 

 has its own particular economical protein feedstuffs. 



427. Why animals fatten. When the animal has the chance 

 to eat more food than is required for maintenance and for the 

 production of new muscle, bone, skin, and hair, it usually stores 

 this food in the form of fat and may use it later when food may 

 be scarce. When the animals were running wild their store of 

 fat was the only protection they had against hard times. 



Man consumes large quantities of fat for food. Since the 

 earliest times he has used various vegetable oils, such as olive 

 oil, for this purpose. When man learned how to grow grain in 

 large quantities he soon took advantage of the fat-producing 

 power of domestic animals. Strains or breeds were developed 

 which were specially capable of producing fat in large quan- 

 tities and economically. Dairy cows capable of producing their 

 own weight of butter fat in a single year were developed. 

 Many breeds of so-called lard hogs were developed. Strains of 

 beef cattle capable of fattening very young have been produced. 



The greatest development in fat production has been within 

 very recent years, since corn production has been so extensively 

 developed, corn being the greatest fat-producing grain known. 



