8 N. H. Agricultural Experiment Station [Bulletin 303 



pen. The latter required 39.6 per cent more time. This was in spite of 

 the fact that cleaning the pens under electric brooding required an 

 average total of one hour and thirty-three minutes more time. The 

 floor of the coal house was dry at all times, but the litter in the electrical- 

 ly brooded pens was quite often damp necessitating frequent removal 

 of litter. 



Table II presents in brief the comparative costs of labor and fuel 

 used under the two methods of brooding. It is to be noted that at the 

 rates of charge for the two fuels there is a cost advantage with the elec- 

 tric brooding method of 52c per brood of 250 chicks. 



Table II. Comparative Cost Record Per Brood of 250 Chicks of Labor and 

 Fuel for Electric and Coal Brooded Pens. 







o 



-3„ 



g^ I I I-. Ill ^1 



^S =". •« § °£S "§ •^a. -s-s 



Ho U%j: Ui 5 0.gw 1-1 S OP. H si o 



Ave.: Electric lOaSVa $3.08 42G $12.78 $15.86 



Ave.: Coal 14:19y2 4.30 ...'. 1512 $12.08 16.38 



* About seventy per cent of the electric consumers in this State now have 

 available a 2-cent rate for current after the first 90 kilowatt hours are 

 consumed. 



Two more bales of shavings were used in the electrically brooded 

 pens than in the coal brooded pens. Giving this a cost value of 25c per 

 bale (local price) and adding to the total costs, there would be but a 

 very small cost differential between the two methods. 



Insulated Floors (With Natural Ventilation Brooders) 



Experiments on the insulated floor construction began in Novem- 

 ber, 1934, and temperature readings were taken with both recording 

 thermometers and thermocouples at intervals throughout the winter. 



The temperature record of one week in which there were three cold 

 days with quite low temperatures at night and three days when the 

 temperature was generally above freezing is shown in Figure 2. 



The two upper curves show the temperature taken in Houses 13 

 and 14 by laying the bulb of the thermograph (measuring 1" diam. and 

 12" long) on the surface of the floor imbedded in the litter under the 

 brooder so that it touched the floor along its length. Inasmuch as the 

 contact with the floor was tangential and small in amount, this reading 

 is composite of floor, litter, floor draft and some chick contact. The 

 temperature of the wood flooring itself is shown later by the readings of 

 the thermocouples which are in direct and complete floor material con- 

 tact. 



