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 0° 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.’ 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 0° 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. Ina stable for 12 cows 
1 These figures are taken from Prof. F. H. King’s book on 
“ Ventilation.” 
