Nicarbazin Residue in Tissues from Broilers Reared on Reused Litter Conditions

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 When NCZ was withdrawn from feed, DNC residues dropped to 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.

Keywords: DNC residues; chemical residues; chicken breast fillet; chicken liver; liquid chromatograph; poultry farming.

Figure 1

Schematic illustration of experimental setup.

Figure 2

DNC residues in chicken liver at 42 days for all treatments (T1-T3). T1: NCZ at 125 mg/kg fed from 1 to 21 d; T2: NCZ at 125 mg/kg fed from 1 to 32 d; T3: NCZ at 40 mg/kg plus maduramicin at 3.75 mg/kg fed from 1 to 32 d; NCZ-free feed (withdrawal period): 22 to 42 d for T1; and 33 to 42 d for T2 and T3.

Figure 3

DNC concentration in poultry litter used for rearing multiple flocks of NCZ-fed broilers at 1, 21, 32 and 42 days of age in Treatment 1 (T1) (a), Treatment 2 (T) (b), and Treatment 3 (T3) (c). T1: NCZ at 125 mg/kg fed from 1 to 21 d; T2: NCZ at 125 mg/kg fed from 1 to 32 d; T3: NCZ at 40 mg/kg plus maduramicin at 3.75 mg/kg fed from 1 to 32 d; NCZ-free feed (withdrawal period): 22 to 42 d for T1; and 33 to 42 d for T2 and T3.