Performance Evaluation of a Passively-Aerated Plastic-Wrapped Composting System Designed for Emergency Disposal of Swine Mortalities

Abstract

Monitoring of a passively-aerated plastic-wrapped mortality composting system designed for emergency disposal of diseased swine highlighted the importance of the physical characteristics of materials used to envelop the carcasses. Inadequate moisture was a problem when using envelope materials such as ground cornstalks or straw having low density and high air-filled porosity. High O 2 concentrations throughout these materials, and significantly higher moisture levels in the top layers than in the materials surrounding the carcasses, suggested significant air movement and transport of carcass moisture away from the carcasses, resulting in carcass desiccation and incomplete decay. Although internal temperatures and moisture levels in test units constructed with corn silage were much more favorable than in those constructed with cornstalks or straw, less carcass decomposition occurred. Settling and compaction, resulting in high bulk density and low air-filled porosity, caused low O 2 concentrations that appeared to impair carcass decay in the silage test units. Abstract.Monitoring of a passively-aerated plastic-wrapped mortality composting system designed for emergency disposal of diseased swine highlighted the importance of the physical characteristics of materials used to envelop the carcasses. Inadequate moisture was a problem when using envelope materials such as ground cornstalks or straw having low density and high air-filled porosity. High O 2 concentrations throughout these materials, and significantly higher moisture levels in the top layers than in the materials surrounding the carcasses, suggested significant air movement and transport of carcass moisture away from the carcasses, resulting in carcass desiccation and incomplete decay. Although internal temperatures and moisture levels in test units constructed with corn silage were much more favorable than in those constructed with cornstalks or straw, less carcass decomposition occurred. Settling and compaction, resulting in high bulk density and low airfilled porosity, caused low O 2 concentrations that appeared to impair carcass decay in the silage test units.

Pile Structure in Large Animal Carcass Compost Piles: Zone Differences in Physical and Chemical Characteristics

“…This zone is remarkable in the fact that it is so highly compacted that it is difficult to penetrate the layer, even with a small spade. This is consistent with findings by Ahn et al (2007Ahn et al ( , 2008, Glanville et al (2007), and Schaub-Szabo and Leonard (1999). It was also 'stickier' and held together more than other layers.…”

“…Ahn, et al (2007) and Glanville et al (2007) reported on a study in which swine carcasses were composted inside a plastic wrapped pile. Moisture levels were checked at the top, middle, and bottom of the test piles.…”

“…The study on swine composting reported by Ahn et al (2007) and Glanville et al (2007) also included measurements of bulk density at different locations with the piles. They found significant bulk density differences between the three zones tested.…”

A Biosecure Composting System for Disposal of Cattle Carcasses and Manure Following Infectious Disease Outbreak

“…As well, Pollard et al (2008) included contained composting as one of the most desirable options for carcass disposal in a recent risk assessment of exposure to AI. Biosecure composting has also been used as a means of disposing of swine carcasses (Ahn et al, 2007; Glanville et al, 2007) although to date biocontainment composting has not been assessed for its ability to dispose of carcasses arising from disease outbreaks in cattle.…”

Effect of low initial envelope material moisture content on swine tissue degradation in layered livestock mortality composting systems

“…The effectiveness of mortality composting systems for the disposal of mass mortalities during catastrophic or emergency situations has been reported in previous papers (Benfeldt et al, 2006;Glanville et al, 2007;Glanville, 2006b;Spencer et al, 2004). These papers outline the ability of mortality composting to be adapted to handle a large volume of mortalities, utilizing a variety of systems and envelope materials.…”