Response of Nigerian farmers to a questionnaire on chloramphenicol application in commercial layers.

The authors assessed the occurrence of chloramphenicol (CAP) residues in commercial eggs. Of the 105 farmers surveyed for the use of CAP, 35 (33.3%) and 70 (66.7%) responded regarding their awareness or complete lack of awareness of the legislation that stipulates the use of CAP in food animals, including poultry, respectively. Only 28 (26.7%) of respondent farmers were aware that CAP was one of the drugs that is not recommended for use in food animals. Amongst the farms surveyed in the preliminary phase of this study, 24 were randomly sampled for further investigation, of which 21 (20.0%) admitted the use of CAP in forms of human and veterinary preparations, while 15 (62.5%) admitted the use of human CAP preparation only. The presence of antimicrobial residues was confirmed using specific thin-layer chromatography (STLC) in 8 out of 144 pooled egg samples (10 eggs per sample). The only positive CAP sample was identified on a farm that adopted the use of a human CAP preparation.