Scientific Abstract
This project focused on the mass carcass management of about 1200 destroyed market-weight swine using grinding and mixing. Objectives were to evaluate management, compost activity, and aesthetics associated with increasing amounts of tissue in the windrow core, to determine throughput, and to compare manual temperature collection with dial-analog thermometers to electronic, remote, sensor technology. Methods. Compost windrows, 12 feet wide x 6 feet tall, were built to compare four different windrow core animal tissue densities: 10, 15, 20, and 25 lb. of ground swine carcasses per cubic foot of carbon amendment. The core windrow animal tissue densities were achieved by feeding a 950-hp horizontal belt grinder carcasses and mulch, simultaneously. A loader with 2 yd3 bucket placed mulch onto grinder infeed conveyor. Carcasses were loaded onto grinder infeed conveyor using a 295-hp excavator equipped with a root rake and hydraulic thumb. A loader with 10 yd3 bucket received the tissue-mulch mixture as discharged from the grinder and placed it into compost windrows. The core compost mixture of ground tissue and mulch was placed upon a 1-foot-deep windrow base of mulch that had been laid down using the 10 yd3 bucket-payloader and the excavator. Windrows were capped or covered with 6 to 8 inches of mulch using both loaders. Windrows were monitored daily for temperature, leachate, flies, vermin, odor, and change in shape. The composting system was operated continuously for one hour to assess throughput. Temperatures were measured using electronic, remote sensors and dial analog thermometers at the same windrow locations to evaluate and compare temperature monitoring methods. Results. Windrows appeared different depending on animal tissue density. With greater densities there was more aggregation of animal tissue as the material was being ground and spread into the windrow. Animal tissue density did not alter composting activity. There were no visual or structural differences in any of the windrows. All were dry, yielding a little odor, and few flies. The maximum throughput of the carcass management system used in this demonstration was estimated to be 10 carcasses every 35 seconds or 1028 carcasses per hour (267,429 lb. or 134 tons per hour). The two temperature methods gave different values. The average absolute value of the differences between temperatures taken using the remote probe or the dial analog thermometers, at the same location and depth, ranged from 4.4 to 15.1 degrees Fahrenheit different. Conclusions. Findings of this project enhance the preparedness of farms to respond to a highly consequential disease outbreak on their farm using a grinding and mixing system. Composting greater tissue densities will lessen the resources/costs necessary to manage carcasses. Dial-analog thermometers will continue to provide the accuracy needed to document compost activity and pathogen elimination.
