Forums Address Rendering's Role in Carcass Disposal and Managing Biological Hazards

By Annel K. Greene, PhD, Center Director, Clemson University, Animal Co-Products Research and Education Center


The 3rd International Symposium on the Management of Animal Carcasses, Tissue, and Related Byproducts: Connecting Research, Regulations, and Response was held July 21-23, 2009, at the University of California Davis in Davis, CA. The event showcased various research projects conducted on carcass disposal and featured discussion forums on procedures for emergency and disease outbreak events. Numerous scientific studies also were presented via the conference poster session.

The majority of the scientific data introduced at the conference related to composting animal mortalities. Clemson University Animal Co-Products Research and Education Center (ACREC) researchers presented the only rendering-related scientific study in a poster that described ACREC’s study validating the destruction of avian influenza via rendering processes.

The magnitude of potential carcass disposal issues was brought into focus by discussions of emergency events impacting confined animal feeding operations around the country. Because of the potential scope of the issue, challenges exist in disposal of animal carcasses in case of a major depopulation event. In an example given, burial of large-scale mortalities from a beef feedlot could require not just a few acres of land but perhaps 50 to 100 acres or more depending on animal populations. Composting in the Midwest region of the country could be especially problematic because of limited available carbon material to add to the compost for promoting bacterial action. Landfill deposition of carcasses poses numerous problems including the need to backfill with other materials to prevent landfill slides upon carcass decomposition.

Various federal and state governmental agency personnel, including the U.S. Department of Agriculture’s (USDA’s) Animal and Plant Health Inspection Services (APHIS), participated in the symposium. The role of rendering was discussed for carcass disposal in depopulation events. Discussions related to rendering centered on (1) the need for safe transport to rendering facilities; (2) ability to schedule large volumes of materials through rendering cookers; (3) validating destruction of disease-causing pathogens via rendering; (4) worker safety; and (5) development of standard operating procedures for cleaning and disinfecting the rendering plant after processing depopulated carcasses to allow resumption of normal operations. Attendees recognized the need for research to assist in planning for emergency depopulation events.

Forum on Managing Biological Hazards in Rendering
On August 18, 2009, an educational forum was presented at Clemson University by rendering experts representing the Animal Protein Producers Industry (APPI). The goal of the forum was to instruct Clemson’s ACREC personnel about issues related to management of biological hazards in rendered products and various feed safety challenges for rendered animal products, including the impact of the Food and Drug Administration’s (FDA’s) Reportable Food Registry. Traveling to Clemson to present the forum were David Kirstein, director of Technical Services at Darling International, Inc.; Dr. Ross Hamilton, vice president for Government Affairs and Technology at Darling International; Dr. David Meeker, senior vice president, Scientific Services, National Renderers Association (NRA)/APPI; and Dr. Sergio Nates, president of the Fats and Proteins Research Foundation. Approximately 25 Clemson University food microbiologists attended and learned about the current challenges and needs of the rendering industry.

Kirstein opened the forum with a presentation entitled “Managing Biological Hazards in Rendered Products through Process Controls,” in which he described industry methods of preventing product failures via hazard analysis and critical control point processes. He discussed the growing considerations among regulatory agencies regarding process controls over production of feed ingredients and animal feed. Kirstein explained the good manufacturing practice safety controls already in place in the rendering industry as well as the APPI Code of Practice that established the “minimum practices and accreditation process that promotes the safety of rendered animal proteins and fats for feed use.”

Hamilton presented “Pathogen Destruction by Rendering: the Need for Validation Tools,” where he discussed the role of rendering in sustainability for the food animal industries and explained the process of rendering. He continued by posing the question, “Why is validating pathogen destruction important?” and then discussed the implications of this for disease prevention, governmental requirements/regulations, and the economic viability of the rendering industry. Hamilton stated that the Food, Drug, and Cosmetic Act (FDCA) definition of “food” is defined as “articles of food or drink for man or other animals – including components of any such articles.” He further explained that FDA’s Center for Veterinary Medicine (CVM), in its Compliance Policy Guide (CPG), “interprets the FDCA to allow different standards for foods intended for human use versus feed intended for animal use [CPG 7126.20 and 7126.24].”

In the past, FDA/CVM promulgated that rendered products are safe (CPG 7126.24). However, Hamilton explained that after September 8, 2009, FDA may approve “only processes that are scientifically validated to kill the pathogen before approving plans to divert recalled food to animal feed.” Clemson ACREC microbiologists joined in a discussion of thermal death time and the progress/challenges that have occurred in the continuing quest to derive this information. In research supported by the rendering industry, Clemson has made major progress in addressing unique challenges in bacterial enumeration from high fat rendered materials. With this newly discovered information, ACREC personnel will be able to continue research on validation of pathogen destruction via rendering.

Meeker presented “Feed Safety Challenges for Rendered Products,” in which he described real, market, and regulatory challenges in the industry. He discussed the scientific needs for proving and improving the rendering process for removal of hazards. The scientific needs described were identification of pathogens including the species, virulence, and incidence within rendered products. Meeker further indicated the need for validation of pathogen destruction and documentation to support process controls.

The forum allowed an excellent discussion with Clemson ACREC microbiologists and rendering industry experts. Several pertinent research projects were identified for assisting the industry in meeting the challenges of managing biological hazards in rendering processes and products. Educating the researchers on industry needs is critical to helping ACREC personnel best serve the rendering industry.

After meeting with the microbiologists, the rendering team met with ACREC researcher Dr. Charles Gooding to discuss the carbon footprint project that is currently underway at Clemson University. Gooding is finalizing a calculator that will assist renderers in evaluating their carbon emissions.

APHIS, NRA, and ACREC Meeting
Meeker and Dr. Annel Greene of Clemson University ACREC met with environmental engineer Lori Miller and veterinarian Dr. Darrel Styles of USDA/APHIS National Center for Animal Health Emergency Management on September 8, 2009. The conference was held at the NRA headquarters office in Alexandria, VA. Research needs for carcass disposal in emergencies were discussed, with the development of standards for cleaning and disinfecting rendering processing plants for resumption of normal operations listed as a priority. Other projects addressed included validation of thermal destruction of various pathogens via rendering as well as development of a current summary of the rendering industry needs including the consequences of regulations/events on the economic viability of the industry.

Clemson University ACREC has a select team of microbiologists and food scientists ready to address development of standard operating procedures for plant clean-up after processing of carcasses from a depopulation event. Members of ACREC previously worked on validation of rendering for destroying major pathogens such as avian influenza; this team will continue to work in this area with other pathogens. Important strides have been made by ACREC researchers in developing methodology for verifying destruction of viral and bacterial pathogens that will assist in accomplishing the next critical research in development of thermal death time values and validated pathogen destruction.


ACREC Solutions – October 2009 RENDER | back