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N. H. Agricultural Experiment Station [Bulletin 303 



3. Intestinal disturbances in chicks as a cause of mortality. 



4. Lung congestion (pneumonia) as a cause of mortality. 



5. Chicks have been brooded at a wide range of temperature. 

 Inasmuch as the standards of temperature and brooder ventilation 



were established by the writers, this fact can not be held as a failure of 

 the equipment. On the other hand, the evenness of maintaining a 

 given temperature throughout the area under the canopy is a function 

 of the brooder itself and is affected by brooder design. 



Power Ventilation 



One of the more recent developments in electric brooder design has 

 been the addition of power ventilation in the form of a fixed speed mo- 

 tor-driven fan, running continuously. This has not changed the method 

 to an "automatic system" but simply boosts the fixed values to higher 

 ratios of air supplies per hour per watt of heating element. This, in 

 turn, reduces the effective heat in the brooder compartment. From the 

 standpoint of temperature alone this raises the question whether the 

 same result cannot be obtained by reducing the amount of electrical heat 

 generated and omitting the forced draft effect. 



The condition of the air under the brooder as regards moisture and 

 general quality would appear to require a definite number value of ajr 

 changes per hour not now known. ^ 



Restlessness-^AcXWiiy or movement of chicks during the night period 

 has been a constant factor throughout the four years of tests. Wliile 

 this chick movement may be attributed to the restlessness of young 

 individuals, there appears to be more than is normal. This is probably 

 a result of improper temperature and air conditions. (See charts of 

 chick movement.) 



Chicks crowding beyond curtain, (taken by photo-flash lamp at night), a 

 condition frequently observed throughout the experiments. 



