Verification of Poultry Carcass Composting Research through Application during Actual Avian Influenza Outbreaks

Abstract

An avian influenza outbreak in 2002 affected 197 poultry farms in Virginia and cost an estimated $130 million in losses and cleanup. In 2004-2005, researchers initiated a project to investigate the feasibility and practicality of in-house composting of turkey mortalities (heavy hens and toms) as a method of disposal and disease containment. Occurrences of low pathogenic avian influenza (LPAI) in West Virginia and Virginia in 2007 provided an opportunity for first responders to verify composting as an effective carcass disposal method. Many lessons learned from these experiences have led to improvements in the application of this technology. Market-weight turkeys, once thought too large for effective composting, were composted sufficiently for land application within 4 to 6 weeks. Additionally, fire-fighting foam, a new method of mass depopulation, proved to be compatible with composting. Knowledge gained from these incidents will be valuable not only for future responses to LPAI but also for outbreaks of highly pathogenic avian influenza such as the H5N1 virus, which currently causes disease in both animals and humans in many parts of the world. Since three-quarters of all recent emerging infectious diseases (EIDs) have arisen from animals, control of disease in animals is the principal way to reduce human exposure and prevent EIDs. Many of the general approaches and specific techniques used to eradicate the avian influenza virus can also be used to control other EIDs such as H1N1, Nipah virus, Rift Valley Fever, and plague.

Comparison of water-based foam and carbon dioxide gas mass emergency depopulation of White Pekin ducks

“…Although foam can take longer for ducks to reach unconsciousness than CO 2 gas on an individual basis, when set-up before depopulation and clean-up after depopulation of an entire flock are taken into consideration, foam offers additional savings in time and labor . Foam also has potentially better biosecurity because the birds do not leave the house, fewer people are needed to enter the house, and in-house composting is compatible with foam depopulation, which means that infected waste does not have to leave the building (Benson et al, 2008;Flory and Peer, 2010). Water-based foam results in longer times to unconsciousness and death than CO 2 gassing approaches when tested on individual ducks.…”

“…Carbon dioxide gas causes hypercapnic hypoxia, by displacing the oxygen in the air surrounding the bird as well as decreasing the pH of the blood (Gerritzen et al, 2006b). Water-based foam was used to depopulate approximately 50,000 turkeys positive for LPAIV in 2 separate incidents in 2007 (Flory and Peer, 2010). A previous study by Benson et al (2009) showed that foam can be successfully used to depopulate ducks; however, the time it took for the animals to reach unconsciousness and brain death was not recorded and only a limited number of birds were used in the study.…”

Efficacy and efficiency of poultry carcass composting using different mechanical mixing equipment for avian influenza outbreaks

“…Composting has been shown to be an effective means for virus neutralization in AI outbreaks and is now considered one of the preferred methods in the US [15][16][17]. According to a study in 2003, the AI virus in manure is neutralized within 15 min at 56°C (133°F), 24 h at 30-37°C (86-99°F) and 2 days at ambient temperatures of 15-20°C (59-68°F) [18].…”

“…In addition, in a study by Glanville et al [22], biosecurity was demonstrated to be highly effective when the compost piles were capped with sufficient non-infected carbon material. Due to its low transportation costs and the creation of a usable, marketable end-product as a soil amendment, composting is the most cost-effective means of disposal as well as the most environmentally sound and biosecure and carries a positive public perception [15,17].…”

“…However, in 2004, during an outbreak on the Delmarva Peninsula in Pennsylvania, composting was successfully used with 5-pound broilers to control the spread of the virus [24]. This led to research in 2004 in Virginia with 40-pound market weight turkeys that confirmed composting is successful if done properly [15,17]. The Virginia research also showed that crushing, shredding, or tilling of the carcasses can speed the degradation and optimal temperatures by opening the carcasses and releasing and distributing moisture, increasing surface area to volume ratio, and exposing the bones to decomposition.…”