Mar., 1938] Electric Brooding of Chicks, II. Heat Requirements 25 



with Brooder No. 2A shows that there was 2^/2 times more current con- 

 sumed per unit of area or contents without extension rims, and extra 

 curtain, as there was with these two features added ; however, total con- 

 sumption per chick was not materially different. No change was made 

 in the number of chicks carried under the brooder. 



This result appears to add emphasis to the vulnerability of brood- 

 ers at the curtain edge and support previous deductions that great 

 losses occur at this point. It also raises the question as to size of brood- 

 er with respect to the number of chicks carried. 



Summary of 1935-36 



The brooder extension group was operated most economically from 

 the standpoint of kilowatt hours of electricity consumed. 



By the use of extension rims and extra curtain on brooder, as pre- 

 viously explained, variations in brooding temperatures were consider- 

 ably reduced ; the temperatures for the most part were held within a 10- 

 degree Fahrenheit range. 



A comparison of three types of artificial floors as used under brood- 

 er — namely, elevated wire mesh, raised floor pad (insulation) and floor 

 pad with heat — exhibited variable effects on brooder temperatures. 

 The elevated wire mesh floor produced erratic and great changes of 

 temperature under the brooder. The same characteristics with slight 

 modifications appeared in the case of the raised floor pad. The floor 

 pad giving under-heat showed the greatest effect in stabilizing tempera- 

 ture under the brooder, maintaining a 5-7 degree regulation. 



The chicks under all three brooder conditions averaged to weigh 

 slightly over one pound at six weeks of age. The type of brooder con- 

 dition did not significantly affect weight, feed consumption, condition 

 or feather growth. Percentage mortality for the experimental period 

 varied from 2.03 in heated pad group to 3.3 in brooder extension group. 



1936-37 EXPERIMENTS 



With a continuation of the premise that the brooder and its imme- 

 diate surroundings should be the focal point of our observations, a de- 

 tailed study of chick movement was made in 1936-37, An attempt was 

 also made to answer questions that had been raised in the field as to the 

 effects of confining chicks in electric brooders over a period longer than 

 six weeks. 



Chick Action Under Brooder 



Detailed observations were made of the hovering conditions of the 

 chicks under the three types of electric brooders from 7 P. M. to 6 A. M., 

 when outside temperatures were at about 32 degrees F. All brooders 

 were fitted with a strip of celluloid in place of a portion of the regular 

 brooder curtain. A mirror was then affixed to the side wall of the 

 house and adjusted to such an angle that observations of chick action 

 under the brooder could be made from the observation booth attached to 

 the opposite side of the colony house. The attraction light under hover 

 allowed for visibility of under-brooder conditions. To determine ac- 



