16 N. H. Agricultural Experiment Station [Bulletin 303 



Relation of House Floor Area to Brooder Size 



From the work done up to this time, especially with respect to floor 

 insulation, it appears desirable to establish not only the space allot- 

 ment under the brooder, but the amount of space which is most desir- 

 able outside of the brooder for ranging and feeding. This involves the 

 relation between size of brooder and size of compartment or house in 

 which it is used. 



Table IV shows that only about 15% of the total floor area 

 is exposed to a controlled heating effect (under brooder) in the case of 

 52'' square or 56" round brooders in 10'xl2' houses. The balance, or 

 85% of the floor, is exposed on its top surface to brooder house air 

 temperatures and floor drafts for the full 24 hours, this being tempered, 

 as indicated in the curve of Figure 3, by sunlight, when and if avail- 

 able, in varying amounts for about eight hours at the most in winter 

 weather. In the case of the same brooders in 12'xl6' houses, the un- 

 heated floor area becomes about 90% as against 10% heated. 



This uncovered floor surface can and does receive, when available, 

 sun heat on an average of one-half of its surface for not more than a 

 maximum of eight hours per day or a net desirable exposure in area- 

 time value of about 16%. If tliis 16% exposure develops the amount 

 of improved temperature regulation that is indicated in the under- 

 floor space, it appears that any method that would improve this action 

 would be desirable. 



The factors involved in this improvement process are considered to 

 be as follows: 



1. Balancing of size of brooder to total size of floor or vice-versa. 



2. Providing maximum exposure possible of uncovered floor to 

 sun's action. 



3. Elimination of floor drafts — air cooling action. 



a. Tight banking up at base of houses. 

 Table V shows the space allotments as used in these experiments, 

 according to periods or intervals of time. 



Summary 1934-35 



The results of the 1934-35 season, added to those of the preceding 

 years, reduced to negligible proportions the significance of insulation 

 or need of particular structural features in any surface of the house 

 enclosing electric brooders. The factors affecting the heat require- 

 ments of chicks were narrowed down to the brooder itself, or conditions 

 existing immediately adjacent to it. By the elimination of the need 

 for any particular or special construction, relieving the practical opera- 

 tor from additional overhead costs, additional confirmation of the 

 feasibility of cold room brooding was obtained. 



Labor requirements in caring for a group of chicks brooded by elec- 

 tricity were less than for coal brooded chicks. More frequent clean- 

 ings of electric brooded pens were necessary, and cost for litter in this 

 method was correspondingly higher. Inasmuch as some more atten- 

 tion and labor attends any experimental set-up, it is likely that our 

 costs may differ from common practice. It appears that with prices 



