Characterisation and screening for antimicrobial substances of slaughtered cattle in Zaria, Nigeria.

The occurrence of antimicrobial drug residues in 500 routinely slaughtered cattle in Zaria, Nigeria, was determined. A microbial inhibition test with Micrococcus luteus ATCC9341 was used to test urine at the time of slaughter for the presence of antimicrobial substances. Thirty-seven (7.4%) of the urine samples were positive for antimicrobial substances. Positive cases were not distributed according to breed (P>0.05), but occurred significantly more in male cattle aged 3-9 years and in those with good body condition score (P<0.05). Thirty-eight cases, in the form of 16 different pathological conditions, were seen from visual inspection of carcasses. Lymphadenopathy was seen in 10 (23.7%) carcasses including one antimicrobial substances positive carcass. Dermatophilosis and emaciation constituted 15.8 and 13.2% of pathological conditions observed, respectively.