Presence of Acetamide in Milk and Beef from Cattle Consuming AFEX-Treated Crop Residues.

Preeti Mor,Farzaneh Teymouri,Amrish Tyagi,Brandon Van Soest,W Allen Julian,Venkataraman Bringi,Bryan Bals,Diane Haddad,Ramin Vismeh,A Daniel Jones,Michael Vandehaar

doi:10.1021/acs.jafc.9b04030

Abstract

AFEX treatment of crop residues can greatly increase their nutrient availability for ruminants. This study investigated the concentration of acetamide, an ammoniation byproduct, in AFEX-treated crop residues and in milk and meat from ruminants fed these residues. Acetamide concentrations in four AFEX-treated cereal crop residues were comparable and reproducible (4–7 mg/g dry matter). A transient acetamide peak in milk was detected following introduction of AFEX-treated residues to the diet, but an alternative regimen showed the peak can be effectively mitigated. Milk acetamide concentration following this transition was 6 and 10 ppm for cattle and buffalo, respectively, but also decreased over time for cattle while tending to decrease (p = 0.08) for buffalo. There was no difference in acetamide concentration in the meat of cattle consuming AFEX-treated residues for 160 days compared to controls. Further investigation is necessary to determine the metabolism of acetamide in ruminants and a maximum acceptable daily intake for humans.

Highlights

The total demand for animal food products is expected by FAO to more than double by 2030, driven by the growing middle-class population in developing countries.[1]
One approach to ammoniation is ammonia fiber expansion (AFEX), in which crop residues would be treated with anhydrous ammonia at elevated temperatures and pressures for a short residence time
The purpose of this study is to investigate the levels of acetamide formed during AFEX processing and the appearance of acetamide in Received: June 28, 2019

Summary

Introduction

The total demand for animal food products is expected by FAO to more than double by 2030, driven by the growing middle-class population in developing countries.[1]. Ammoniation of crop residues has been well documented to increase their digestibility, no widespread implementation of ammoniation technologies has occurred.[4] One approach to ammoniation is ammonia fiber expansion (AFEX), in which crop residues would be treated with anhydrous ammonia at elevated temperatures and pressures (approximately 100 °C and 2 MPa) for a short residence time (30 min) in packed bed reactors with the ammonia being recovered and recycled at regional collection and processing centers.[5] Ammoniation makes the cellulosic sugar polymers in crop residues more accessible to hydrolytic enzymes and increases the inorganic nitrogen content, which result in increased digestibility of the crop residues in vitro[6−8] and in vivo.[9]

Objectives

Methods

Results