Intraobserver and interobserver reliability of mud scoring systems for use in cattle at slaughter

At slaughter plants, live cattle are often scored for mud coverage as mud on hides can impact food safety and drives decisions regarding interventions during processing. Currently, there is no standardized method utilized to assess mud coverage. The aim of this study was to determine the intraobserver and interobserver reliability of 3, 4, and 5 point mud scoring systems. Beef cattle (n = 110) were videotaped during movement to holding pens upon arrival at a commercial slaughter facility. Five scorers were assigned to a 3, 4, or 5 point scoring system (n = 15), reviewed the video and assigned the cattle a mud score. A multi-rater weighted kappa analysis was used to determine intraobserver and interobserver reliability for each system. Although all scorers in the 3 point analysis and one scorer each for the 4 and 5 point analysis demonstrated moderate intraobserver reliability, all interobserver reliability kappas were poor (kappa ≤0.12). Further exploration to develop a suitable system that is repeatable is recommended.