PROJECT LEADER:
William H. Allen
COOPERATORS:
B. L. Hughes - Poultry Science Department
J. C. McConnell - Animal, Dairy and Veterinary Science Dept.
J. D. Simmons - SCPRL-ARS-USDA
FUNDING AGENCIES:
South Carolina Agricultural Experiment Station
Duke Power Company
Carolina Power and Light Company
South Central Poultry Research Center, ARS-USDA
DESCRIPTION
Litter (wood shavings) under broiler chickens were aerated during six weeks of rearing. Two systems of air flow were compared. A positive pressure system forced air down through the litter to an exhaust plenum while a negative pressure system forced fresh air from a plenum below the litter upward and into the room. Litter moisture contents and ammonia production rates were compared. All treatments were compared to a non-aerated control. The moisture content of the control room litter tended to be higher than the aerated litter. Of the aerated litter, the positive pressure tended to have lower litter moisture than did the negative pressure rooms. However, the room with negative pressure aeration produced less ammonia gas than did the positive pressure aerated room and approximately the same as the control room. Additional aeration trials are planned. A second aspect of this work indicated that a large quantity of the gas could be separated from the general building exhaust and captured in a small quantity of exhaust air. A third aspect of the trials determined the relationship between static pressure and air flow rate through the litter as a function of time. One relationship was determined for each of the six weeks of rearing. These relationships provide data for the design of future litter aeration systems. This effort was sponsored in part as a pilot study by small monetary gifts from Duke Power Company and Carolina Power and Light Company. Efforts to develop an environmental index to characterize thermal environment for brooding chickens continued in the controlled environment of the Godley-Snell Research Center. Air velocity was introduced as a third variable. However, birds did not react as hypothesized by seeking a compensating environment characterized by a constant blackglobe temperature. Preliminary indications may be interpreted to mean that chickens of brooding age may not distinguish effectively between environments characterized by differing air flow velocities. Additional investigations are warranted before adding humidity as the fourth variable.
SIGNIFICANCE
Emphasis upon air quality in and near animal production systems is very important relative to productivity, worker health and general environmental quality in the surrounding community.
Future viability of the poultry broiler production industry is called into question by the perception of the general public and their lawmakers relative to the effect of this industry on the environmental quality of the communities located nearby production facilities. The results of this research will provide valuable and important information regarding feasibility of a potential solution for broiler production facility air quality as affected by ammonia, odor and other hazardous or obnoxious air components. Separation of the gases from the large quantity of exhaust air provides a potentially effective means to implement abatement procedures by allowing treatment of a greatly reduced volume of affected air. Finally, determination of the relationships between static pressure required to aerate litter as a function of bird age provides basics engineering design data required for the design of litter aeration systems.
Development of a blackglobe temperature-humidity environmental index for brooding chickens would extend current knowledge by providing information based upon measurements that more totally integrate the thermal environment and do so for birds younger than previous research. This information would be important for environmental control when brooding chickens and have important implications for the design of environmental control sensors and systems for this industry.