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ARS Home » Plains Area » Bushland, Texas » Conservation and Production Research Laboratory » Livestock Nutrient Management Research » Research » Publications at this Location » Publication #406685
Research Project: Strategies to Manage Feed Nutrients, Reduce Gas Emissions, and Promote Soil Health for Beef and Dairy Cattle Production Systems of the Southern Great Plains

Location: Livestock Nutrient Management Research

Title: Alkaline hydrolysis of poultry carcasses and health risk assessment of exposure to target volatile organic compounds

Author
item SUN, ZHIHUI - University Of Illinois
item AKDENIZ, NESLIHAN - University Of Wisconsin
item BANIK, CHUMKI - Iowa State University
item Koziel, Jacek

Submitted to: Journal of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/27/2023
Publication Date: 3/25/2024
Citation: Sun, Z., Akdeniz, N., Banik, C., Koziel, J.A. 2024. Alkaline hydrolysis of poultry carcasses and health risk assessment of exposure to target volatile organic compounds. Journal of the ASABE. 67(2):141-152. https://doi.org/10.13031/ja.15744.
DOI: https://doi.org/10.13031/ja.15744

Interpretive Summary: Disposal of animals that have died due to disease or injury is a necessary part of livestock production systems. A relatively new disposal method used to dispose of dead animals involves using a highly alkaline process. Despite the effectiveness of inactivating pathogens, this process has not been widely accepted as a practice because of capital and operating costs, as well as potential worker safety concerns. Scientists from the University of Illinois at Urbana-Champaign, University of Wisconsin-Madison, Iowa State University, and USDA-ARS-Bushland, Texas tested the efficacy of this process to dispose of dead chickens. Specifically, they focused on identifying volatile organic compounds (VOCs) emitted during the process; and they estimated theoretical risks to workers of breathing in these VOCs. Concentrations of some VOCs sometimes exceeded their recommended exposure limits. The results indicated that the alkaline process of dead chicken disposal is feasible, but the potential inhalation exposure of workers should be limited to less than 1 hour.

Technical Abstract: Animal carcass management is an essential part of a livestock production system. Alkaline hydrolysis is a relatively new disposal method used to digest and break down animal tissues. Despite the effectiveness of inactivating pathogens, alkaline hydrolysis has not been widely accepted as a disposal method because of high capital and operating costs, especially when done at high temperatures and pressure. The objectives of this research are 1) to test the efficacy of alkaline hydrolysis treatment of poultry carcasses at ambient temperature and pressure, and 2) to identify odor-causing volatile organic compounds (VOCs) emitted from the carcasses during the process and to calculate the health risks of exposure to these VOCs. 1M, 2M, and 4M potassium hydroxide solutions were used to hydrolysate chicken carcasses, and the headspace was sampled using 85 µm Carboxen/polydimethylsiloxane (CAR/PDMS) solid phase microextraction (SPME) fibers. The pH of the hydrolysates stayed above 13.1 during the study, which was a promising result in eliminating pathogens of concern. Concentrations of target VOCs fluctuated over 10 weeks, and concentrations of trimethyl amine, acetic acid, and propionic acid exceeded their recommended exposure limits. It was found that more than 17% of the workers exposed to the headspace gases 3h a day are at a high risk of developing serious chronic health problems. The results of this study indicated that alkaline hydrolysis of chicken carcasses at ambient conditions is feasible, but the exposure to headspace gases should be limited to less than 1h.