Mar., 1938] Electric Brooding of Chicks, II. Heat Requirements 23 



day the characteristics of the curve change but little, but the level of 

 the whole curve moves up about 2 degrees. By Saturday it has be- 

 come stabilized as verified by the repetition in Sunday's record. In 

 other words, it has taken 41/^ days for the brooder to pull conditions 

 back to normal. 



The cause of this upset was the introduction of fresh cold shavings 

 to the floor under the brooder by the cleaning operations of Monday. 

 As a result the brooder spent a large proportion of its energy in heat- 

 ing and drying out this new litter. 



Inasmuch as this cleaning and shifting of shavings is a regular 

 procedure each week, while hovers are fully raised, its relative impor- 

 tance can be pointed to with emphasis. Methods of management to 

 eliminate this difficulty and associated increase in current costs should 

 be considered. 



The use of fresh, dry shavings or litter, preferably taken from a 

 moderately warm storage point, is a step in brooder management to be 

 recommended, and the transfer of shavings from the outer floor area 

 to under the brooder is not a good practice under cold weather brooding. 



Elfect of Heated Brooder Floor 



The results from applying heat to the brooder floor (so-called 

 under-heat) in the manner previously described, are shown in the top 

 curve in Figure 7. 



The general level of this curve is somewhat high, according to our 

 standards, averaging a little over 100 degrees, although some manu- 

 facturers recommend such. This high temperature, we believe, was 

 caused by improper location of the heat-pad thermostat, on which more 

 reliance was placed than on the wattage of the respective elements. 



Since there is a great divergence in opinion as to the optimum heat 

 to be supplied under the brooder, the principal significance of this 

 trial lies in the development of this method as a control measure. 



It will be seen that up to Monday mid-day, the general floor tem- 

 perature was well regulated and high in value. After the cleaning 

 operation and changing of litter a steady decline took place until Tues- 

 day at sunrise. This substantiates the deductions of the same nature 

 just made in regard to cold, damp litter, and appears to be the time re- 

 quired for the heat pad to correct the new litter condition. It is ap- 

 parent, however, that the time required to get the litter back into con- 

 dition in this case is much less than in the previous one. 



From Wednesday through the remainder of the week the tempera- 

 ture stayed approximately within the limits of a 10-degree range. This 

 method, therefore, was about equally effective in range of temperature 

 control to the extensions and additional curtain previously reported, 

 but maintenance of a 20-degree higher level on an average accounts for 

 the extra current consumption. (See Table 6) 



The detail of the curve, however, is quite different in that it is 

 one continuous series of small variations which are attributed to the 

 continued influence of floor drafts. In this connection it is pointed 

 out that no other than regular curtain equipment was employed with 



