Nicarbazin Residue in Tissues from Broilers Reared on Reused Litter Conditions

SIMPLE SUMMARY: The poultry production worldwide needs to use feed additives in order to avoid disease. One of the most common diseases is coccidiosis, which affects the poultry gut. In case the disease happens, birds stop eating, which might cause their death as well as generating great losses to the farmer. Nicarbazin is one of the widely used anticoccidials to prevent coccidiosis. However, some non-compliances have been reported by the regulatory agencies, which made us explore chicken litter to verify if it was a contamination source in chicken tissues because birds have coprophagic habits. Therefore, our team conducted an experiment with three different nicarbazin treatments commonly used in commercial poultry production, under reused litter conditions. We evaluated the possible residue left from this anticoccidial in fillet and liver during 2 years. The outcomes have relevant implications: (a) litter is not a cause of contamination, allowing farmers to reuse it for economical purposes; and (b) chicken tissues are safe for human consumption. ABSTRACT: Nicarbazin (NCZ) is a worldwide used anticoccidial in poultry farming to avoid coccidiosis disease when chickens are reared on conventional poultry litter. If proper dosage and withdrawal time are not followed, the component dinitrocarbanilide (DNC) of NCZ may be present in chicken tissues, therefore posing a risk to consumers if the residues are above 200 µg/kg. Litter reuse is a common and important practice in commercial chicken production. Literature is lacking about the influence of litter reuse on DNC deposition in chicken tissues and its impact on food safety. We aimed to evaluate DNC residues in breast and liver by LC-MS/MS from broilers from an experiment with 10 consecutive flocks during 2 years. The experiment included three treatments containing NCZ in the diet (T1 = 125 mg/kg, 1–21 d; T2 = 125 mg/kg, 1–32 d; T3 = 40 mg/kg, 1–32 d). DNC residues in chicken breast at 21 d in T1 ranged from 648.8–926 µg/kg, at 32 d in T2 and T3 varied, respectively, from 232–667 µg/kg and 52–189 µg/kg. Regarding liver, DNC residues at 21 days in T1 ranged from 11,754–15,281 µg/kg, at 32 days in T2 and T3 varied, respectively, from 10,168–15,021 µg/kg and 2899–4573 µg/kg. When NCZ was withdrawn from feed, DNC residues dropped to <LOQ at 42 d in all treatments. Therefore, the reuse of poultry litter does not compromise food safety regarding DNC residues in chicken tissues, as shown herein up to 10 flocks.