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Weight-shifting and Locomotion Scoring as Measures of Lameness in Dairy Cows: Repeatability and Correlation
This study investigated the repeatability of two measures of lameness in dairy cows: locomotion scoring and rear leg weight-shifting. Correlations between these two measures and the presence or absence of hoof lesions also were explored. Data were obtained from 11 dairy cows classified as “lame” (locomotion score of ≥3 on a 5-point scale) and 11 dairy cows classified as “sound” (gait score <3/5). Each cow was weighed for 5 consecutive days on a scale that measured the weight borne on each leg 11-14 times per second. Each weighing session consisted of 2 to 3, 5-minute sub-sessions of data recording. Prior to weighing on days 1 and 5, video recordings were made of the cows walking; these videos were used to assign locomotion scores on a 5-point scale (1 = not lame, 5 = severely lame). On days 1, 3, 4, and 5 each animal had one weighing session; day 2 consisted of 4 weighing sessions at approximately 3 hour intervals. The standard deviation of weight borne over time was calculated for each foot at each weighing session and used as a measure of weight shifting. For lame and sound cows, mean locomotion scores and weight shifting did not differ within the group over the test period (score: P=0.85; shifting: 0.70). Increased shifting of weight borne on the rear legs was correlated with higher locomotion scores (P=0.003). In addition, the presence of a lesion on the right rear hoof (the most common location) was correlated with increased weight shifting of the right rear leg (P=0.027). Repeatability of weight-shifting measures and their correlation to both locomotion scores and hoof lesions validates weight-shifting behavior as an objective measure of lameness and hoof pain.
Keywords: Lameness, Dairy, Behavior