Poultry Industry Research Papers

Scavengers: Friend or Foe of the Poultry Industry, Jeff Hill, MSc, BS, Livestock Welfare Strategies Traditional composting methods pose biological hazards.

In North America approximately 1,500,000,000 pounds of broiler and 187,500,000 pounds of layer hen mortalities must be disposed of annually. Composting has become the most commonly utilized method of on-farm carcass disposal. However, this method can result in significant biosecurity risk, especially as the current outbreak of HPAI intensifies.

Due to the management requirements to ensure a successful composting process, many producers allow, if not actively encourage, the scavenging of poultry carcasses from their disposal facility. In fact, scavenging of carrion has essentially become a defacto method of carcass disposal, especially in the South and Western US.

Surveys report counting a single to hundreds of scavengers within a poultry mortality composting facility, with producers describing more than a 50% reduction of carcass volume due to scavenging. Many see this as a benefit since this significantly reduces the effort required to manage the composting process and minimizes the amount of carbon resources required.

However, high pathogenic avian influenza (HPAI) is a major emerging disease, a cause of mass mortality in wild birds during outbreaks and a tremendous risk to the North American poultry industry. As described by USDA-APHIS wild birds common at the wildlife–agricultural interface have a high potential to share viruses with poultry when spillover occurs from wildlife to poultry, and then potentially spills back from poultry to wildlife.

Wild birds are considered natural reservoirs of avian influenza virus (AIV) and at least 105 species of wild birds have been reported to harbor these viruses. Surveillance programs have shown the highest number of detections of HPAI in wild birds occurs in waterfowl species. However, the second highest number of detections occurs in scavengers and birds of prey. There is a common misconception in the industry that vultures (often referred to as buzzards) are not infected, not carriers, nor can they transmit HPAI. This has again been proven false, as recently the National Veterinary Services Laboratory confirmed cases of Highly Pathogenic Avian Influenza (HPAI) strain: H5 2.3.4.4 in black vultures. (Florida Fish and Wildlife Conservation Commission, 2/22/2022).

Scavengers are infected predominantly by ingesting infected prey as their feeding behavior is as an opportunistic predator and scavenger which has the potential to expose it to HPAI-infected prey. These birds may ingest a high quantity of infected meat and, therefore, are considered to be at high risk of becoming infected with HPAI, spreading the virus prior to dying of related diseases.

The spread of HPAI between poultry premises almost always follows the movement of contaminated people and equipment. With large flocks of scavengers roosting, feasting and defecating within the mortality composting facility it is highly likely that the HPAI virus will spread from the fecal matter of scavengers deposited within the composting shed to the poultry production barns on the bottom of boots, vehicles, or equipment.

Are the benefits of scavenging really worth risking your birds, your operation and even your industry?