June, 1942] Agricultural Experiment Station 5 



At Western Washington, Shoup and Smith (5) reported that in 

 control houses it was necessary to change the litter every 4 to 14 days 

 during the rainy season in order to have reasonably dry litter in the 

 houses, the exact time between changes depending on the moisture 

 content of the litter. When they used artificial heat in the houses they 

 found that a one degree increase in temperature decreased the mois- 

 ture content of the air by 4%. In the houses that were warmed they 

 state that the litter was at all times in good condition when changed 

 only once a month. 



Carver (6) also at Washington, reported that under the climatic 

 conditions at Puyallup, it was impossible to provide dry litter by the 

 use of controlled ventilation in an insulated or uninsulated curtain 

 house. He states that the difference in temperature between the floor 

 and the air above the. floor causes condensation of moisture. Carver 

 (7) also states that in a straw loft house with which he was working, 

 the litter would often reach a moisture content of 30%, reaching this 

 figure within a week after it was placed in the house, yet the moisture 

 in the straw in the straw loft averaged about l2^/o and the straw did 

 not seem to absorb moisture from the litter. 



While the forgoing writers indicate that heating the house is a 

 desirable practice, Lee and others (8) state that the use of heat in an 

 uninsulated house with which they were working in central New York 

 State, resulted in a lower annual egg production, slightly lower feed 

 consumption, occasionally a lower litter requirement and a serious 

 and consistent lowering of the net flock income. 



On the other hand, Smith (9) working at Nebraska found that the 

 maximum egg production was obtained when the temperature of the 

 house was not permitted to vary widely. He states that the exact 

 temperature range to be maintained is not of much importance, but 

 it is important to pick a fairly narrow range and maintain it. 



Kennard and Chamberlain (10) in a discussion of winter housing 

 for layers said that the air in an insulated house is warmer and damp- 

 er than the outside air. This warm inside air is pushed out of the 

 house through open doors and windows or through cracks and cre- 

 vices in the wintertime by the colder, heavier, dryer outside air. As 

 the warmer air leaves the house it carries out a large amount of mois- 

 ture with it. 



They state that the condition is somewhat different in an unin- 

 sulated house in the winter as the outside and inside temperatures are 

 practically the same, therefore, there is not this movment of air and 

 so the uninsulated house is damper than the insulated one. 



Heywang (11) studying the water consumption of hens found 

 that two pens of Rhode Island Red hens consumed 19.8 and 19.9 gal- 

 lons of water, respectively, per hen per year. He made allowances for 

 evaporation from the water pens. Increases in air temperature, live 

 weight, and rate of production tended to increase water consumption 

 and decreases in any of these factors tended to decrease water con- 

 sumption. In some cases, he reported that the effect of increases in 



