Assessment of Oxytetracycline and Penicillin G Residues Levels in Raw and Fermented Milk in Maiduguri, Northeastern Nigeria

Abstract

This study was conducted to evaluate the presence and concentration of Oxytetracycline and Penicillin G residues in raw cow and Fermented milk consumed in Maiduguri, Northeastern Nigeria. A total of 172 (86 raw and 86 fermented) milk samples were randomly collected from different milk selling points in Maiduguri. A Spectrophotometer ultraviolet visible spectrum machine was used to detect and quantify the oxytetracycline and penicillin G residues in the milk samples. All samples (raw and fermented milk) tested positive for oxytetracycline and penicillin G residues with a mean residual concentration of 36 µg/L and 20 µg/L in raw and fermented milk respectively for oxytetracycline while the mean residue concentration of penicillin G is 649 µg/L and 397 µg/L in raw and fermented milk respectively. However, the oxytetracycline residues detected were all below the Maximum Residue Level (MRL) standards of 100 µg/L, while the penicillin G residue detected were all above the maximum residue standard of 5 µg/L. The maximum and minimum residue for oxytetracycline detected in raw milk was 79 and 10 (µg/L) respectively while the maximum and minimum residue detected in fermented milk was 42 and 9 (µg/L) respectively. The maximum and minimum residue detected for penicillin G residue in raw milk was 1993 and 767 (µg/L) respectively while the maximum and minimum residue detected in fermented milk was 288 and 164 (µg/L). This study revealed the presence of both oxytetracycline and penicillin G residues in raw and fermented milk consumed in Maiduguri. However, oxytetracycline residues detected in this study were found to be within the acceptable limits, while the penicillin G residues were highly above the MRL standard set by CODEX.