|HINTON, JR., ARTHUR|
Submitted to: Agriculture, Food and Analytical Bacteriology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 19, 2010
Publication Date: May 4, 2011
Citation: Dunkley, C.S., Cunningham, D.L., Ritz, C.W., Dunkley, K.D., Hinton Jr, A. 2011. Using mortality compost in vegetable production: A comparison between summer and winter composting and its use in cabbage production. Agriculture, Food and Analytical Bacteriology. 1:6-14. Interpretive Summary: Experiments were done to examine the use of composting to recycle carcasses of broiler chickens that had died in a commercial poultry house. The study was conducted during summer and winter months to compare the effect of environmental temperatures on the process. Dead broilers were collected from a local poultry grower on 4 consecutive days and added to a compost bin. Samples were collected from the compost bin on every other day for 1 week after the container was filled, and then once per week until composting was completed. The temperature of the compost was monitored and bacterial analysis of the compost was conducted during the process. Finished compost was used as a soil amendment in two vegetable plots planted with cabbage seedlings. Microbial analysis of cabbage and soil was conducted periodically until the cabbage crop was harvested. Findings showed that the temperature of the compost reached 156°F after 9 days during the summer and after 42 days in the winter. No Salmonella were recovered from compost material 2 days after beginning composting. Only low levels of coliform bacteria were recovered from the cabbage plot after harvesting. Results indicate that composting of dead broiler carcasses can be successfully used to recycle carcasses during summer or winter months and that it is safe to use this compost to augment soil in vegetable plots.
Technical Abstract: A study was conducted to determine the effectiveness of composting to breakdown the carcasses of daily poultry mortality and in the process destroy pathogenic microorganisms that may be present. The study was conducted during the summer and repeated in the winter to determine whether the time of year would affect the temperature profile or the length of time required for the process to be completed. Daily mortalities were collected from a nearby producer and layered in a compost bin each day for four days. Samples were collected from the litter before it was placed in the bin. Compost samples were collected every other day for a week after the bin was compiled and then once per week until the process was completed. The samples were evaluated for microbial content. Temperature was taken and recorded at random points in the bins on a daily basis. Upon completion of the composting process, the material was used as a soil amendment in two vegetable plots while a third plot without compost material served as the control. Soil samples were collected from each of the plots prior to application of the compost material. Cabbage seedlings were then planted in each of the plots. Vegetative samples and soil samples were collected and evaluated for microbial presence prior to planting and at week, 1, 3, 7, and again at reaping. The summer compost had the highest temperature of 156°F on d 9 during the primary phase while the winter compost had the highest temperature of 156°F on d 42 during the secondary phase of the compost. The summer compost samples were Salmonella enterica (SE) negative from d 2 of the trial but mixed bacterial colonies remained for the duration of the study. The vegetative samples in plot 1 had coliform levels of 3.48 log10/gm at wk10 but the levels was not considered significantly different from the other two plots (p<0.05). The results show that while winter composting can effectively breakdown poultry carcasses and attain high temperatures, summer compost is more efficient and had consistently higher temperatures.