Conventional versus modern abattoirs in Colombia: Impacts on welfare indicators and risk factors for high muscle pH in commercial Zebu young bulls

The aim of the study was to determine the effects of abattoir type (conventional abattoir -CA- versus modern abattoir -MA-) on stress parameters and risk factors for high muscle pH in Colombia. A total of 522 Zebu young bulls were studied in two groups: 285 at CA, and 237 at MA. Blood samples were taken to measure cortisol, glucose, lactate, creatine kinase, β-hydroxybutyrate, total protein, albumin, creatinine, urea, haematocrit, leukocytes and N/L ratio. Cattle were monitored during the unloading, lairage, handling and stunning. The logistic regression model showed that stocking density, transport time, abattoir type, and inefficient stunning were variables associated with the prevalence of dark cutting carcasses. This study demonstrated that modern improvements at abattoir level, proper infrastructure, and stunning equipment, do not always guarantee quality in terms of animal welfare. As a first attempt in the Colombian beef industry, this research suggested how handling practices could affect cattle welfare and the prevalence of high muscle pH even at MA.