Rendering and Avian Influenza

During the 2014–2015 outbreak of highly pathogenic 

avian influenza (HPAI), the U.S. Department of 

Agriculture’s (USDA) Animal and Plant Health 

Inspection Service (APHIS) conducted several 

epidemiological studies to identify potential 

transmission pathways. While these studies did not 

determine exactly how the outbreak spread, they 

identified potential risk factors for being affected 

by the HPAI virus, such as sharing equipment 

between farms, proximity to other affected farms, 

and rendering dead birds.

In light of these findings and some confusion about 

using rendering as a routine mortality management 

practice, APHIS is clarifying how its findings relate to 

rendering. There is a distinction between the widely 

accepted practice of rendering itself and failures to 

properly manage that practice in connection with 

storage, transportation, and/or personnel.

Rendering Basics

Rendering is the process of converting byproducts 

of the farming and food processing industries into 

safe, useable products. These products include 

both edible and inedible products, including feed 

for livestock or pets, soaps, and biofuels. Materials 

to be rendered typically come from slaughter 

plants, but may also include restaurant waste 

and on-farm mortalities. 

During the rendering process, pressure and 

heat raise the temperature of the materials to 

approximately 245° to 290° F (115o to 145o C) for 

40 to 90 minutes, while evaporating moisture and 

separating fat, protein, and bone. This process 

also kills bacteria, protozoa, parasitic organisms, 

and viruses, including highly pathogenic and low 

pathogenic avian influenza virus. 

To protect livestock health and ensure that feed from 

rendered materials is safe, the rendering industry 

established a voluntary feed safety program. The 

program is based on good manufacturing practices 

and process controls. Certified renderers who 

follow these guidelines produce safe, quality 

feed ingredients.

The Role of Biosecurity

Epidemiological studies show an association between 

avian influenza (AI) presence on poultry farms and 

the use of rendering to dispose of daily mortality. An 

APHIS study of table egg farms, conducted during 

the 2014–2015 HPAI outbreak, found two risk factors 

for farm infection related to rendering—having the 

dead bird disposal area near barns and allowing 

rendering trucks to come near the barns. 

APHIS determined the cause of this association 

between AI and rendering is most likely biosecurity 

breaches during the movements of dead birds, 

trucks, and people between poultry operations, 

NOT the use of rendering as a mortality disposal 

process itself.

There are several practices that can substantially 

reduce the risk of spreading germs and diseases. 

Renderers and producers alike should work together 

to implement the following:

• cleaning and disinfecting rendering trucks

• picking up dead birds at a location that’s not 

near production areas

• reducing the frequency of dead bird 

pick-up by increasing on-farm dead bird 

storage capacity

• ensuring that on-farm dead bird storage 

is operated in a biosecure manner 

(i.e., closed/sealed to prevent access by 

animals and insects)

• preventing contamination of trucks and 

personnel (either at the rendering facility 

or at previously visited farms) 

• using dedicated storage bins at each location 

that do not leave that location and are not 

shared by multiple facilities

For More Information

If you have questions, contact APHIS’ Centers for 

Epidemiology and Animal Health at (970) 494-7200 

or ceah@aphis.usda.gov.

ANIMAL AND PLANT HEALTH INSPECTION SERVICE NOVEMBER 2016 

VETERINARY SERVICES

APHIS 91-55-105 USDA is an equal opportunity provider, employer, and lender.