DAIRY INSPECTION 137 



will answer quite well. A cow requires 59 cubic feet of 

 air per minute, or 3540 cubic feet per hour. To provide 

 this amount for a cow occupying a space of 500 to 600 

 cubic feet, it would be necessary to entirely change the 

 air in the space occupied by the cow six to seven times 

 per hour. It is estimated that the heat given off by a 

 cow in 24 hours is equal to 76,133 British thermal units, 

 which is sufficient to heat 79,603 cubic feet of dry air 

 from to 50 F. This quantity of air would provide 

 3316 cubic feet of air per hour, only 224 cubic feet less 

 than the quantity required by the cow. 1 It would appear, 

 therefore, that the required amount of fresh air could 

 be admitted to a stable with 500 to 600 cubic feet of air 

 space per cow without lowering the temperature too 

 much, especially since the temperature only rarely falls 

 to F. in the dairy sections in the northern part of the 

 United States. The most comfortable temperature for 

 the dairy cow is from 60 to 65 F., but if the temperature 

 is kept lower by ventilation, say down to 50 F., the cow 

 will not suffer in health and the milk flow will not be 

 reduced, provided exposure to the low temperature be- 

 gins in the autumn and is continuous. Milk cows have 

 been kept through the winter in sheds open to the south 

 with quite satisfactory results. 



The distribution of the cubic air space is important. 

 If the ceiling is too high, the stable is likely to be cold at 

 the level occupied by the cows, although the upper part 

 may be warm enough. The height of the ceiling should 

 be regulated by the size of the stable. Eight feet is a 

 sufficient height for small stables. In a stable for 12 cows 



1 These figures are taken from Prof. F. H. King's book on 

 " Ventilation." 



