CHAPTER IV 



MAINTENANCE OF FARM ANIMALS 



I. REQUIREMENTS FOR BODY FUEL 



Farm animals are given food in order that they may convert it into 

 such products as meat, milk, wool, and work, which are useful to man. 

 However, just as a factory must be supplied with power to keep the 

 machinery in motion before any products can be turned out, to make 

 continued production possible with the animal, enough food must first 

 be provided to maintain all necessary life processes. 1 This amount of 

 food, which is required merely to support the animal when doing no 

 work and yielding no material product, is called the maintenance ration. 

 A respiration trial conducted with an animal receiving a maintenance 

 ration would show that its body was neither gaining nor losing protein, 

 fat, or mineral matter. 



On the average, fully one-half of the feed consumed by farm animals 

 is used simply for maintenance, only the remaining half being turned 

 into useful products. Knowing this, the intelligent feeder will realize 

 that it is just as important to understand the principles governing the 

 maintenance requirements of farm animals as those controlling the pro- 

 duction of meat, milk, or work. The determination of the minimum 

 amount of nutrients required for maintenance is also of great scientific 

 importance, for it is impossible to find the true relative value of feeding 

 stuffs for production without first subtracting the amounts used in mere 

 maintenance. 



To maintain an animal at rest the ration must furnish sufficient 

 amounts of the following: (1) Fuel to maintain the body temperature; 

 (2) energy to carry on such vital processes as the work of the heart, 

 lungs, etc.; (3) protein to repair the small daily waste of nitrogenous 

 tissues; (4) mineral matter to replace the small but continuous loss of 

 these materials from the body; (5) vitamines, which recent investigations 

 have shown to be just as necessary as the nutrients previously considered 

 essential. For all classes of animals, other needs which must be supplied 

 are air, water, exercise, and sunlight. 



87. Body temperature. While cold-blooded animals maintain their 

 temperature but little above that of the surrounding air or water, the 

 temperature of warm-blooded animals ranges from 98.4 to 105.8 F., 

 a height which the air reaches only during the hottest summer days. It 

 is therefore evident that heat must be continuously produced within the 

 body to keep it at such temperatures. 



1 Armsby, Penn. Bui. 111. 



56 



