168 



POULTRY CULTURE 



from a contaminated source. It is essential that pure air be 

 supplied. 



In ventilation we have three factors to consider— namely: 



1. The amount of fresh air required. 



2. The method by which fresh air can be suppUed. 



3. The method of examining to determine whether ventila- 

 tion be sufficient. 



Fig. 58. — Diagram showing currents of air through a poultry house. The 

 air entering at a passes under the dropping board and above the dropping 

 board at h and g, but no draft strikes the birds on the roosts at /. The air 

 passes through the house as indicated by the arrows and out at c. For cold 

 climates it is desirable to have a front drop curtain immediately in front of 

 the birds and at the front of the house, as indicated in the drawing. The 

 curtain material must allow of the passage of air through it. 



The amount of fresh air required by average size fowls is 

 8278 cubic feet per thousand pounds live weight each twenty- 

 four hours. 



Russel estimates that an average sized fowl breathes about 

 1.2 cubic feet of air per hour or one foot per minute. Each 

 bird should be provided with ten cubic feet air space. Geese 

 and turkeys should have 40 cubic feet per bird. 



There is a method whereby a physical test may be made to 

 fairly accurately arrive at the amount of carbon dioxid that is 



