Composting for Biocontained Cattle Mortality Disposal and Associated Greenhouse Gas and Leachate Emissions

Abstract

Composting can be an effective means of biodegrading livestock mortalities in emergency disposal situations, such as disease outbreaks. Within the past decade, our knowledge detailing composting has increased substantially. However, research data linking the environmental impact of composting to atmospheric and terrestrial systems are limited. We investigated composting efficacy, greenhouse gas emissions, and leachate properties from two static compost piles, each containing 16 cattle mortalities, built with either beef manure (BM) or wood shavings (WS) as envelope material. Wood shavings achieved a greater maximum temperature than BM (60 vs. 50°C) and maintained higher temperatures over 200 d ( < 0.001). Greenhouse gas emissions were evaluated using a static chamber and gas chromatography. Emissions of NO ( < 0.001), CH ( < 0.01), and CO ( < 0.05) were lower from WS than BM, resulting in 3-fold lower total CO equivalent emissions. After 250 d of composting, piles were relocated, and soil cores were taken (i) from beneath the piles, (ii) adjacent to the piles where leachate had accumulated, and (iii) in a control zone without compost exposure. Elevated concentrations of ammonium ( < 0.05) and chloride ( < 0.05) were found in soil beneath both BM and WS. Microbial DNA profiles suggested that leachate from BM compost increased bacterial diversity in soil, maintaining a biological soil impact after pile removal. Degradation of bovine mitochondrial DNA fragments was monitored by polymerase chain reaction. Limited migration of genetic bovine material from compost into soil was observed. Based on the mortalities decomposition and leachate contents, both BM and WS are suitable envelope materials for composting.

The use of composting for the disposal of African swine fever virus‐infected swine carcasses

“…Land‐fill burial has the same disadvantages as on‐farm burial. In addition, transporting animal carcasses from farms to landfill sites requires of a number of available trucks and may lead to the introduction of disease to other areas (Gilroyed et al., 2016; Hayama et al., 2015; Wilkinson, 2007). Incineration is an effective disposal method for destroying contagious viruses by high temperatures; however, it is expensive due to the need for fuel and incinerators (Ducey et al., 2017; Gwyther et al., 2011).…”

A review of the animal disease outbreaks and biosecure animal mortality composting systems

“…Despite the development of new vaccines and the application of rigorous biosecurity measures, animal diseases pose a continuing threat to animal health, food safety, the national economy and the environment (Wilkinson et al, 2011). Intense livestock production, increased travel, and changing climate have increased the risk of catastrophic animal losses due to infectious diseases (Gilroyed et al, 2016;NRCS, 2015). Management of these diseases is essential in view of the threats they pose to health, farm incomes, and the viability of animal agriculture.…”

“…The 2001 FMD outbreak in the United Kingdom required the disposal of 6.5 million animals and created major difficulties to manage mortalities (Guan et al, 2010). Transporting mortalities to disposal facilities outside the production operation is a challenge that introduces new biosecurity risks (Gilroyed et al, 2016). Burying mortalities is limited by the size and availability of suitable sites and it has the risk of pathogen survival and contamination of groundwater and soil (Bonhotal et al, 2009).…”

A Comparative Study of Swine Tissue Composting With Woodchips, Rice Husk And Wheat Straw

“…Animal carcasses are of high mass, high moisture content, high nitrogen content and zero porosity (Wilkinson, 2007), suggesting their difference from livestock and poultry manure in composting processes. Animal carcasses can not be mixed with materials evenly, which are usually placed in the center of the compost and covered with animal manure or some materials of good porosity, high carbon, low nitrogen(straw, corn silage or wood shavings) (Gilroyed et al, 2016). The composting of pig carcasses needs to undergo two processes: static stacking of carcass degradation and a maturation stage similar to the composting of livestock and poultry manure (Harper et al, 2009).…”