June, 1942 J Agricultural Experlment Station 



weight of the sample and pie pan after the final stage of drying from 

 the original weight of the sample and pan. The wet weight of the 

 sample was obtained by subtracting the weight of the pan from the 

 initial weight of the sample and pan. The per cent of moisture was 

 determined as a ratio of the grams loss of moisture to the gram weight 

 of the wet sample. Thus, if one sample has a moisture percentage 

 of 50 it means that a 300 gram sample would contain 150 grams of 

 water and 150 grams of dry litter material. 



Although the moisture content of the wet sample is 50%, refer- 

 ring to the dry sample it would be 100%. The calculations given here- 

 in are all made on the basis of weight of water to wet weight of sam- 

 ])le. A sample containing 50% moisture, then, really consists of equal 

 weights of litter and of water. 



EFFECT OF SAMPLE DRYING UPON PLOT HOUSE 

 AND POULTRY PEN LITTERS 



Each week a sample of litter was taken from each pen of the 

 ])lot house, brought into the laboratory and kept in the drier for about 

 two weeks. At the end of this time the dry sample was returned to 

 the plot house. Thus a sample leaving the plot house with 10 to 18 

 per cent moisture was returned at 0-|- per cent moisture. Each plot 

 contained approximately 5,000 cubic inches of litter and the sample 

 removed had a volume of approximately 50 cubic inches. Thus, it 

 would require 100 samplings to have dried out all of the litter in one 

 plot, providing each removal consisted of litter not previously used. 

 In actual practice some litter particles were dried more frequently 

 than others. The average sample consists onl}^ of one per cent of 

 the total volume. 



It is evident that humidity conditions in the air influence the 

 litter samples to cause a gain or loss from week to week. It seems 

 logical to assume that the dry litter returned to the plot soon assumed 

 tlie degree of humidity of the rest of the plot, Avhich is in apparent 

 equilibrium with the air moisture. In an}^ case, the effect of drying 

 the litter samples would be small. 



The poultry pen litter is not aff'ected by the return of dry samples 

 because (I) the sample is so small in comparison to the amount of 

 litter, and (2) because of the much greater humidity condition of the 

 poultry pen. Assuming the average litter depth to be at least L)4 

 inches, the pen litter would have a volume of 100.000 cubic inches. 

 The sample is but 0.05 per cent of this total as compared to the 1.0 

 per cent for the plot samples. 



GENERAL MANAGEMENT FACTORS 



The birds used in this experimental study are listed by pens on 

 the general summary tables. Pens 15, 16, and 17, contained each year 

 representative New Hampshire pullets from regular pedigreed 

 matings and so far as possible all pens were identical as to bird com- 

 plement. The birds of other breeds used were carefully selected for 



