Abstract #505

# 505
Dynamics of activity around corrective and therapeutic hoof trimming.
S. Paudyal*1,2, G. Solano1, P. Melendez3, I. Roman-Muniz1, R. Callan4, F. Maunsell5, J. Velez6, P. Pinedo1, 1Department of Animal Sciences, Colorado State University, Fort Collins, CO, 2Texas A&M University, College Station, TX, 3Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA, 4Department of Clinical Sciences, College of Veterinary Medicine, Colorado State University, Fort Collins, CO, 5Department of Clinical Sciences, College of Veterinary Medicine, University of Florida, Florida, Gainesville, FL, 6Aurora Organic Dairy, Platteville, CO.

Hoof trimming (HT) in dairy cattle is associated with stress and may result in temporary alterations in behavior and production. Our objective was to characterize the dynamics of activity and milk yield (MY) in animals submitted to HT during early lactation. HT (n = 265) was classified into corrective (CHT; n = 190) and therapeutic (THT; n = 75), when a foot disorder was concurrently diagnosed. A total of 310 multiparous Holstein cows from a dairy herd in northern Colorado were afixed with a pedometer (IceQube, IceRobotics, Edinburgh, UK) in one rear leg at 12 ± 8 DIM and monitored for 7 mo for lying time (LY; min/d), number of steps (ST; n/d), lying bouts (LB; n/d), and MY (kg/d). Cohort cows not submitted to HT were considered as healthy controls (HCT). Average daily values for each activity variable and MY were compared with controls within ± 7-d relative to HT. In addition, activity data and MY were categorized into low and high, relative to the median to evaluate their ability on predicting HT categorization. Associations between behavior, MY, and HT were tested by use of mixed linear models and logistic regression analyses. Parity, DIM, access to pasture, and presence of estrus were included in the models. Overall, 21, 21, 10, and 23 cows were diagnosed with foot injury, digital dermatitis, foot rot, and non-specific lameness, respectively. Daily LY was greater in THT, followed by CHT and HCT (626 ± 24; 573 ± 12; 563 ± 8.2 respectively; P < 0.001). LB was greater in THT, followed by HCT and CHT (19.6 ± 1.17; 18.7 ± 0.02, and 18.5 ± 0.49; P < 0.01). ST and MY were smaller in THT (2,016 ± 121; P < 0.001; 36.0 ± 1.3; P = 0.2) compared with CHT (2,610 ± 121 and 37.9 ± 0.8) and HCT (2,664 ± 7.9 and 36.2 ± 0.04), respectively. High LY and high LB categories were associated with greater odds (CI) of THT (OR [95%CI] = 2.60 [2.14–3.19] and 1.80 [1.50–2.19] respectively), whereas high ST category was associated with reduced odds of THT (0.2 [0.1–0.16]) and CHT (0.4 [0.24–0.77]). The magnitude of the changes in activity behavior in cows subject to HT was greater when locomotion disorders were present, as compared with CHT.

Key Words: hoof trimming, lying time, activity