1909.] The Construction of Cow Houses. 



553 



as inlets for the air, and the same in the roof for its exit, 

 rather than any special system of ventilation. No class of 

 building is so easily ventilated as that which is open to the 

 ridge, and in none may the system which is adopted be so 

 simple and inexpensive. The great requisite is to provide for 

 each animal plenty of inlet area, which should not be less 

 than 40 sq. in. per cow, irrespective of doors or windows, 

 which should be reserved for exceptional weather, and if the 

 situation is at all sheltered more should be provided. It 

 does not follow that all available ventilation should be always 

 utilised, but sufficient openings should exist to keep the air 

 fresh — say, 8 to 12 of carbon dioxide per 10,000 volumes 

 when the stock are in, and the air is calm. These openings 

 should be provided with some arrangement by which the 

 inlet of air can be easily regulated to suit the conditions of 

 weather. For instance, if the wind is strong the volume of 

 air which will pass through any opening will be many times 

 greater than when it is calm, and it is to provide for such 

 occasions that some system of regulation is necessary. The 

 old system of putting straw in the openings in stormy weather 

 cannot be recommended, as when a change of weather occurs 

 the straw is almost invariably in when it should be out, and 

 out when it might be in. The outlet ventilating openings 

 should not be less in area than the inlets, and may with 

 advantage be 100 per cent, greater. Like the inlets, the 

 outlets should be provided with some system of partially 

 closing them when it is desired to do so. 



The simplest and one of the most serviceable of inlet 

 openings is a flat one, 24 in. by 4 in., or 18 in. by 6 in., in 

 the wall opposite each double stall. This opening should be 

 between 5 and 6 ft. from the floor if the animals are stalled 

 with their heads to the wall, but if a passage intervenes.it 

 may be somewhat lower, as in this case the current of cold 

 air becomes modified and diffused in its course across the 

 passage, and before it reaches the cows. If a board 9 to 12 in. 

 broad and 24 in. long is placed flat along the bottom of this 

 opening, and the edge next the outside of the wall is hinged 

 in any convenient manner, an arrangement can be easily fitted 

 up by which each or all of these boards can be raised, so as 

 I to reduce wholly or partially the incoming current of air. 



