The University of New Hampshire [Bulletin 338 



1940, with 43.80 inches of rain, had nearly 6 inches more than usual. 

 The greatest precipitation during any month of 1940 occurred in No- 

 vember, when 6.92 inches fell, while less than .25 inches of rain fell 

 during the entire month of October. Rainfall is generally distributed 

 fairly evenly throughout the year ; September averages 3.52 inches 

 and is the wettest month, while February, with 2.83 inches, is the 

 driest month. During 1940, 54 inches of snow fell in Durham. Rain 

 fell on 120 days of 1940 and 155 days were clear. 



Winds are prevailing from the northwest in Durham during the 

 winter while southwest winds are more common in summer. Sea 

 breezes are often felt in Durham during the latter part of spring and 

 summer afternoons and often bring a sudden drop in temperature." 



OBJECTIVE 



The general objectives of this experimental study were to deter- 

 mine methods for the elimination of excessive moisture in poultry 

 house litter to reduce the spread of disease, labor of cleaning, and 

 costs of operation and to improve sanitation, appearance, general 

 management operation and the physical condition of poultry house 

 litters. 



REVIEW OF LITERATURE 

 Dann (1) reported that the rate of evaporation of water from the 

 litter depends on the available heat, the rate of air movement over the 

 litter, the frequency of turnover of the litter, and its depth. Dann 

 maintained that when the temperature of the litter is higher than the 

 temperature of the air above it, the entrained air in the litter will hold 

 more moisture and so the evaporation frorn the litter will be hindered. 

 As deep litter has more spaces with entrained air than shallow litter, 

 Dann felt that deep litter would not dry as readily as shallow litter. 

 Therefore, he recommended that the floors of houses not be heated 

 and that a litter not to exceed four inches in depth be used. 



This statement is directly contrary to conclusions from the West- 

 ern Washington Experiment Station by Miller, Smith, and Svinth 

 (2) that warming the floor of the houses Avill maintain dry litter. 

 These authors also conclude that cooling of poultry house floors by 

 direct exposure to outside air is usually conducive to wet litter. They 

 state, however, that it is not desirable to heat poultry house proper in 

 order to dry the litter. 



Miller, Gordon, and Gushing (3) at Washington found that it 

 was possible to maintain dry litter when the rate of egg production 

 and the climate were favorable for the production of wet litter by 

 keeping the floor 7.50° warmer than the air just above the floor. They 

 stated that they were unable to keep the floor dry by either slow or 

 rapid ventilation. 



Card and Moore (4) at Michigan also reported that warming the 

 floor keeps the litter dry. They placed an electric heating element 

 in the floor of the house. 



