Impact of Slaughter Age and Preslaughter Conditions on Microbiological Quality of Beef in Kaduna State

Preslaughter stress and animal age at slaughter are known determinants of both carcass quality and microbiological safety in beef production systems. This study examined the impact of slaughter age and preslaughter conditions on the microbiological quality of beef in Kaduna State, North West Nigeria. Structured data on animal age, transport duration, holding period, and preslaughter handling were collected for 150 cattle at Kawo Abattoir. Immediately post-slaughter, carcass swabs were taken from the brisket, rump, and flank surfaces for aerobic plate count, Enterobacteriaceae count, and Salmonella isolation. Regression modeling assessed the contribution of preslaughter variables to microbiological outcomes. Results showed that animals held for fewer than six hours post-transport had significantly higher Enterobacteriaceae counts than those rested for 12 or more hours. Older animals above 36 months showed lower contamination rates, possibly reflecting differences in skin microbiota and hide integrity. Salmonella prevalence was 18.7% overall, with the highest rates in animals from long-distance transport. Multivariate analysis identified transport duration and resting period as the strongest predictors of total aerobic count. The study concludes that preslaughter management, particularly adequate rest periods, substantially reduces microbiological contamination of beef carcasses. Mandatory resting requirements and improved pre-slaughter holding facilities at Kaduna State abattoirs are recommended. Keywords: preslaughter conditions, beef microbiology, slaughter age, abattoir, Kaduna State