, BULLETIN No. 459 ¥& 
= 
i 
= ty 
A Get 
LAN 
\ IT 
a ay, ‘\ 
: 
q 
Contribution from the Bureau of Animal Industry. 
A. D. MELVIN, Chief. 
Washington, D. C. Vv December 15, 1916 
THE USE OF ENERGY VALUES IN THE COMPUTATION OF 
RATIONS FOR FARM ANIMALS.! 
By Henry Prentiss Armssy, Director of the Institute of Animal Nutrition of The 
Pennsylvania State College; Expert in Animal Nutrition, Bureau of Animal Industry. 
CONTENTS. 
; Page. Page. 
Cemerilprincipless ese cwye seas Seas oe Se 1 | The computation of rations—Continued. 
Components of the animal body..-...-... 1 improvement. ola Tation es 264. cS eau sie 21 
Components of feeding stufis....-.....-.. 3 Computing a ration from given feeding 
The animal body as a machine...-...... 4 SGU Geta ON eas cn aes nea umn 22 
Heed ereqguInementSe me 2 ee an Sete: 14 The choice of feeding stufis..-...22:.-.-- 25 
The computation of rations...........-...--- 19 The compounding of rations............-. 28 
General considerations. -2- 4225-0. /. 22.2. 19 Bearing on farm management........... 29 
Motaliecdsrequired == 4262224 552 ob ace 20 
GENERAL PRINCIPLES. 
COMPONENTS OF THE ANIMAL BODY. 
THE MACHINERY OF THE BODY. 
The essential working parts of the body contain a great variety of 
substances, but these may, for our present purpose, be grouped 
under three heads—water, ash, and protein. The bones, consti- 
tuting the framework of the body; the ligaments, muscles, and 
tendons, which bind together and move the bones; the skin and 
hair, or wool, which cover and protect the body; the internal organs 
of circulation, respiration, digestion, excretion, and reproduction; 
the brain and nerves—in short, the whole mechanism of the body— 
can be regarded as being composed substantially of these three 
classes of substances. 
Water.—Rarely less than half and sometimes as much as three- 
fourths of the weight of the live animal consists of water. The 
1 A revision of Farmers’ Bulletin 346. 
60978°—Bull. 459—16——1 
