Abstract Mobility scoring is a practical indicator of animal welfare that captures how cattle move and interact with their environment, integrating dimensions of biological function, comfort, and behavioral expression as described in the Three Circles model of animal welfare. Continued increases in finished weights of U.S. cattle, monitoring mobility remains an important welfare priority. The objective of this study was to evaluate the effects of dietary fat and growth promotants on mobility and gait scores of fed cattle. A total of 475 finished cattle at the US Meat Animal Research Center (Clay Center, NE) were observed as they exited the chute and moved towards holding pens over four collection days during summer 2025. Cattle were enrolled in a larger growth promotant and dietary fat supplementation study. Each animal was assigned a mobility score (1-4; North American Meat Institute mobility scoring system) and a gait score (Walk, Trot, or Run) by a single observer. Mobility score (SCORE) was analyzed using a linear mixed-effects model with dietary fat (FAT), feed additive (TRT), and their interaction (FAT × TRT) as fixed effects, and pen and population included as random effects. Gait classification (GAIT) was analyzed using a cumulative link mixed model with the same fixed and random effects structure. No significant main or interaction effects were detected for either outcome (p 0.35). Mean mobility scores ranged from 1.92 to 1.99 across treatment combinations, and gait distributions (Walk = 76.8%, Trot = 22.5%, Run = 0.6%) were consistent across treatments. These findings indicate that dietary fat inclusion, feed additive type, and their interaction did not influence mobility or gait in this study. Across all cattle mobility scores ranged from 1 to 3 (mean = 1.99, median = 2), with 7.8%, 85.3%, and 6.9% of cattle scoring 1, 2, and 3 respectively. Most cattle were observed walking (76.8%; n = 365), followed by trotting (22.5%; n = 107), and running (0.6%; n = 3). Mean mobility scores were similar across gaits (Walk = 1.99; Trot = 1.99; Run = 2.00), indicating no significant differences. These results suggest that the NAMI mobility scoring tool produces consistent outcomes across gaits. The absence of treatment effects on mobility and gait suggest that the evaluated feed additives did not negatively impact cattle locomotion under the conditions studied. However, the high proportion of cattle scoring a “2” indicates mild but prevalent mobility issues that warrant further investigation, particularly as finished weights continue to increase. Future research should evaluate mobility longitudinally throughout the finishing period to better understand when and why changes in movement occur.
Woiwode et al. (2026) studied this question.