58 FEEDS AND FEEDING, ABRIDGED 



breathed. To provide cows with air of this purity, there should pass 

 into the stable for each cow not less than 85,000 cubic feet of air each 

 24 hours.* These figures show the necessity of providing some ade- 

 quate system of ventilation when animals are confined in closed 

 stables, as are horses and dairy cattle during the winter in the north- 

 ern states. 



Water. — Animals can live much longer without solid food than 

 without water. An abundant supply of water is necessary for all the 

 vital processes of the body, such as the digestion and absorption of 

 food nutrients and the removal of waste from the body. As already 

 shown, water is also an agent in regulating the body temperature, 

 both thru the vapor given off by the lungs and the evaporation of 

 sweat from the surface of the body. 



Scientists agree that farm animals should have all the water they 

 will drink at regular intervals, for they do not take it in excess unless 

 they are forced to live on watery foods or are given salt irregularly. 

 The water for stock must be fresh and pure to avoid disease. AH 

 water drunk must be raised to the temperature of the body, thus con- 

 suming heat. AA^arming cold water taken into the body does not 

 necessarily mean that more food must be burned, for animals pro- 

 duce a large amount of heat in the M'ork of digesting food and con- 

 • verting the digested matter into body products or work. Due to this, 

 many animals create an excess of body heat. Comfortably housed and 

 well-fed steers and dairy cattle may produce more heat thru this means 

 than is needed to warm their bodies and the excess may go to warm 

 the water they drink, so that no food is directly burned for that 

 purpose. However, when animals are watered but once a day they 

 then drink a large amount. In M'inter if the water is cold this makes 

 a sudden demand for a large amount of heat, which may exceed the 

 amount of excess heat being produced in the body. Food must then 

 be burned simply to warm the water, even tho thereafter an excess of 

 heat may be produced in the body. For this reason, feed may be 

 saved by watering frequently animals unduly exposed to cold and 

 those fed scanty rations, or else by warming the water. During 

 severe winter weather cows producing a heavy yield of milk need mdre 

 water than they are apt to drink if it is supplied too cold. Under 

 such conditions their water should be warmed. 



Commonly unappreciated factors in food. — AVithin recent years 

 evidence has been accumulating which shows that the classes of 

 nutrients previously discussed — proteins, carbohydrates, fats, and 

 mineral matter — are not all that is needed to make a satisfactory 

 ration. It has long been known that when humans live for long 



4 From King, Ventilation for Dwellings, Rural Schools, and Stables. 



