Classification of dairy cow excretory events using a tail-mounted accelerometer

•Tail-mounted accelerometer used for dairy cow excretory event classification.•Stratified cross-validation (SCV) and leave-one-cow-out (LOCO) cross-validation evaluated.•>86 % sensitivity and precision for SCV with random forest for excretory events.•<70 % sensitivity and precision for LOCO with random forest for excretory events.•Considerable variation in performance for LOCO classification.