Nicarbazin contamination in feeds as a cause of residues in eggs.
A survey was carried out to investigate the prevalence of nicarbazin residues in eggs in Northern Ireland. Nicarbazin, in the form of 4,4'-dinitrocarbanilide (DNC), was detected in 39 of the 190 eggs analysed. An experiment was designed to establish the relationship between nicarbazin-contaminated feed and nicarbazin residues in eggs. The concentrations of both the DNC and 4,6-dimethyl-2-hydroxypyrimidine (DHP) components of the drug in eggs were proportional to feed levels. The maximum feed nicarbazin concentration of 12.1 mg/kg (8.6 mg/kg DNC and 3.5 mg/kg DHP) gave rise to mean maximum whole egg concentrations of 631 micrograms/kg DNC and 51.8 micrograms/kg DHP. After withdrawal of the experimental diet, DNC was undetectable in eggs after 12 days and DHP after 3 days. Feed contaminated with nicarbazin at concentrations greater than about 2 mg/kg gave rise to egg DNC residues at concentrations greater than the Differential Action Limit (DAL) set by the UK (100 micrograms/kg). DNC was contained almost entirely in the yolk of the egg, whereas DHP was distributed between albumen and yolk in a ratio of approximately 3:1.
Cannavan
A
A
Veterinary Sciences Division, Department of Agriculture & Rural Development, Stormont, Belfast, UK.
Ball
G
G
Kennedy
D G
DG
D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002645:Chickens / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003049:Coccidiostats / Q000032:analysis* / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D004350:Drug Residues / Q000032:analysis*; D004529:Egg White / Q000032:analysis; D004530:Egg Yolk / Q000737:chemistry; D004531:Eggs / Q000032:analysis*; D005260:Female; D005506:Food Contamination / Q000032:analysis*; D013058:Mass Spectrometry; D009528:Nicarbazin / Q000032:analysis* / Q000493:pharmacokinetics; D009660:Northern Ireland
D003049:Coccidiostats; D009528:Nicarbazin