DETECTION OF ANTIMICROBIAL DRUG RESIDUES IN EDIBLE TISSUES FROM BUNAJI CATTLE SLAUGHTERED IN MINNA ABATTOIR

Abstract

Occurrence of antimicrobial drug residues in edible tissues from Bunaji cattle slaughtered in Minna abattoir was investigated during this study. 168 edible tissue samples comprising of meat, liver and kidney were collected from 56 Bunaji cattle slaughtered in Minna abattoir at 2 weeks intervals for a period of 4 months. Antimicrobial inhibition test was used to screened tissue samples for evidence of Antimicrobial drug residues with zone of inhibition measured in millimetres (mm). ELISA test kit was further employed for confirmatory and quantification of oxytetracycline residues from the screened positive samples obtained from the inhibition test. The data obtained were analysed using descriptive percentages and presented as tables for both antimicrobial screening and oxytetracycline residues. Chi- square test was used to test the associations between occurrence of drug residues and other variables. Out of 168 samples screened, 89 (52.97 %) of the samples were confirmed positive for antimicrobial residues at various inhibition zones with values of 29 (51.79 %), 37 (66.07 %) and 23 (41.07 %) obtained for meat, liver and kidney, respectively. There was significant association (P<0.05) between tissue samples screened and antimicrobial residues analysed. Sex variation showed female animals had highest values of 68 (70.78 %) antimicrobial residues distributed at 20 (69.96 %), 29 (78.37 %) and 14 (60.86 %) for meat, liver and kidney respectively, when compared to males with values of 9 (31.03 %), 8 (25.80 %) and 9 (39.13 %) for meat, liver and kidney, respectively. Animals between the ages of 6-10 years had the highest antimicrobial residue values of 56 (62.92 %) above other age groups. The 89 (52.97 %) obtained from screened samples were subjected to quantitative analysis using Elisa kit test, thereafter, overall values of 37 (41.57 %) oxytetracycline residues were detected above maximum residue limits (MRLs), as well as values of 25 (28.08 %), 10 (11.23 %) and 2 (2.24 %) were obtained for muscle, liver and kidney, respectively. There was significant association (P<0.05) between screened tissue samples and oxytetracycline residue analysed. Female animals had 29 (32.98 %) oxytetracycline residues above set limits as against males that had 8 (8.99 %). Age variation indicated 22 (24.71 %) values of oxytetracycline residues above limit for animals within 6-10 years age groups, which was higher than other age groups. From the results, it is clear that consumers of cattle meat in Minna metropolitan are predisposed to health hazards due to consumption of high levels of antimicrobials and oxytetracycline residues in cattle tissues slaughtered in the study area. This emphasised the need for effective ante-mortem inspection of animals in the lairage before slaughtered, general enlightenment on the withdrawal period before the animals are slaughtered and possible establishment of antimicrobial residues monitoring unit in the study area.