Investigation of Nonionophoric Coccidiostat Residues in Feed as a Consequence of Carryover

Abstract

Residues of nonionophoric coccidiostats at carryover concentrations in feedstuffs collected from feed mills or animal farms in central Italy were detected as part of the official controls carried out from 2011 through 2016. The 118 samples were collected on the production line or during feed distribution and storage to determine the sampling sites at major risk of cross-contamination. For determination of nonionophoric coccidiostats, a fast, easy, and cheap method was developed and validated. Feed samples were extracted with acetonitrile-methanol and directly injected for liquid chromatography with tandem mass spectrometry. A total of 24 samples (20.3%) were positive, but only 5 (4.2%) of these samples exceeded the maximum limit set by European legislation. Most of the positive samples were collected from a batch of feed produced immediately following processing of another batch to which the coccidiostat robenidine had been added.

Occurrence and Residue Concentration of Coccidiostats in Feed and Food of Animal Origin; Human Exposure Assessment

“…Among non-ionophoric anticoccidials, the most frequently detected compound was DIC, found in 27 samples, 3 of which were above the maximum residue level, followed by ROB that exceeded the regulatory limit in 1 out of 17 positive samples (Table 3). These results are in partial agreement with Moretti et al [23] and with Annunziata et al [36], whose studies also refer to ROB being the most frequently detected non-ionophoric molecule in feed samples.…”

“…It is to be noticed that the non-compliance rate varies mainly as a result of an increase in samples tested during the years examined, rather than an effective decrease in positive samples. Ionophoric molecules were detected in 28 feed samples (10.4%), while non-ionophoric molecules were found in 54 samples (20.15%); these results differ from those reported by Annunziata et al [1] for ionophoric compounds (32.4%) and are comparable to those reported by the same authors in 2018 [36] for non-ionophoric residues in feed samples (20.3%) collected as part of the official Italian monitoring plan in other regions of Italy. Among ionophoric molecules, the most frequently detected coccidiostat in untreated feed was LAS, found in 11 samples, one of which exceeded the regulatory limit, followed by NAR found in 7 samples of which one was a noncompliant sample (Table 3).…”