136 PRINCIPLES AND PRACTICE OF MILK HYGIENE 



of glass and 2 square feet of cloth for each 1000 pounds of 

 animal weight is a good proportion. When the air is still, a 

 stable ventilated by means of muslin-covered windows will not be 

 more than 1 to 3 F. colder than stables in which the King 

 system is used, and there will be 7 to 10 per cent, less humidity 

 in the stable air ; but when high winds prevail, the animal heat 

 will be rapidly dissipated and the stable will be colder. If the 

 cloth becomes wet and freezes, ventilation will cease. 



(b) Cubic Air Space. This is determined by meas- 

 uring the length and width of the stable, multiplying the 

 length by the width, and then multiplying the result thus 

 obtained by the height of the ceiling. After the total 

 cubic feet of air space has been ascertained in this manner, 

 the stanchions or ties should be counted and the total 

 cubic feet of air space divided by the number of 

 stanchions. The result will be the cubic feet of air space 

 per animal. The number of stanchions or ties should be 

 used for this purpose instead of the number of animals 

 present because this method will give the minimum cubic 

 feet of air space per animal under all conditions. 



The size of a stable in proportion to the number of 

 animals in it bears an important relation to ventilation. 

 The less air space per animal the more frequently the 

 air in the stable must be changed. The heat given off by 

 animals is only sufficient to warm a certain quantity of 

 air, and if this limit is exceeded the stable will be cold in 

 winter. A stable with insufficient cubic air spaces will also 

 be hot and uncomfortable in summer. 



It is desirable to have 1 cubic foot of air space for 

 each pound of animal weight, but this amount cannot 

 always be provided because of the cost of building mate- 

 rials and for other reasons. With suitable arrangements 

 for ventilation, 500 to 600 cubic feet of air space per cow 



