EQUIPMENT AND APPLICATION 



Our preliminary studies encouraged us to work with large quantities of 

 excreta in a specially designed device. It consisted of two wooden boxes ,2/ 

 each 24 by 12 by 3 5/8 inches, mounted one on top of the other (fig. 1) . The 

 top box was divided into a center area, 22 by 9 inches, and two end sections, 

 each 22 by 1 1/4 inches. The center section contained the poultry feces; the 

 end sections were air vents that released the ammonia accumulating below. The 

 floor of this box was 1/8-inch mesh hardware cloth. The bottom box was un- 

 sectioned. It had a removable tray, which was a wooden frame covered with 1/16- 

 inch plastic-coated fiber glass screen, supported 2 3/8 inches above the solid 

 wood floor. For best results the inside of this bottom box should be painted 

 black. 



Poultry feces were placed in the center section of the top box to a depth 

 of 2 1/2-3 inches. Then newly laid house fly eggs were seeded onto the feces 

 at a rate of three eggs per gram of feces. The device was placed in a room 

 where it was kept for 7-8 days with continuous overhead light and an air tem- 

 perature of 68 or 80° F. During this time the eggs hatched and the larvae 

 developed and aerated the medium by their tunneling. By the sixth day most of 

 them had passed through the 1/8-inch hardware cloth floor to the tray below. 

 (The continuous light prevented the negatively phototactic fly larvae from 

 wandering upward in search of a pupation site.) Some particles of the larval 

 medium dropped through the hardware cloth to the fiber glass screen tray. This 

 lower screen was sufficiently flexible to allow the vermiform larvae to wriggle 

 through and drop to the solid floor to pupate , but very little medium passed 

 through this screen. 



USABLE PRODUCTS OF EXCRETA CONVERSION 



Large quantities of poultry excreta, about 10-12 pounds, were converted 

 from wet excreta to semidry, crumbly waste in only 8 days, and most of the 

 pupae were separated from the medium by the larval migrations . 



Additional drying and pelleting would now be all that would be necessary 

 to prepare this biodegraded organic waste as a soil conditioner. These pellets, 

 when watered, disintegrate rapidly and do not have the obnoxious odor of fresh 

 excreta. 



A secondary product of the biodegradation is a poultry feed supplement 

 made from fly pupae. Preliminary evidence indicates that with a rate of 

 seeding of fly eggs and the excreta from 100,000 hens we could produce between 

 500 and 1,000 pounds of pupae daily. These dried pupae were shown by Calvert 

 and others^/ to be a satisfactory source of protein for growing chicks. 



2/ Any inert material of a strength comparable to wood would be 

 satisfactory. 



