552 



The Construction of Cow Houses. [oct., 



was 60 per 10,000 volumes of air. At the other farms where 

 this experiment was carried out almost identical results were 

 obtained. The average for twenty-one tests made on five 

 farms in mid-winter gives 12*8 volumes of carbon dioxide 

 per 10,000 of air for the buildings more or less freely venti- 

 lated, and having an average temperature of 49/8 0 F., 

 while a similar number of trials on the same evenings 

 in similar adjoining buildings, but with restricted ven- 

 tilation and an average winter temperature of 59*4° F., 

 the carbon dioxide present was 34*7 volumes per 10,000 

 of air. The results of this experiment emphatically show 

 that there is no gain in purity of the air, corresponding 

 with the cost, in buildings of very large cubic capacity 

 per cow compared with those of more moderate size. They 

 also prove that if any cow-house, no matter what its cubic 

 space per cow, is kept at a temperature of 6o° F. or more, 

 its air will contain about three times as much carbon dioxide 

 than if the building had been freely ventilated and kept at 

 under 50 0 F. While the production of milk may be as great 

 in the one case as in the other, the health of the animals in 

 the freely ventilated building will remain good, while the 

 constitution of the others will gradually become enfeebled. 



If the other details in connection with the construction of 

 the building are attended to, it will be found that fairly good 

 results may be obtained if 420 to 450 cubic ft. are allowed 

 for the smaller breeds of cows, such as Jerseys and Kerrys, 

 and young Ayrshires. Breeds of, say, the size of the Ayr- 

 shire should be allowed a minimum of 500 cubic ft., and the 

 larger breeds, such as Shorthorns, say, 600 cubic ft. While 

 there will be some advantage in increasing these minima 

 by 20 to 30 per cent., little return will be obtained for the 

 money expended in making them any larger. 



Ventilation. — Closely associated with cubic space, but in 

 reality quite a separate subject, is that of ventilation. While 

 a certain floor and cubic space must be provided before the 

 cows can be conveniently and economically attended to, the 

 health of the animals and purity of the milk will in great part 

 depend on the means provided for ventilating the building. 

 Even the thoroughness of the ventilation is much more a 

 matter of providing in the walls ample openings of any kind 



