Abstract #506

# 506
Association between lying behavior and hoof lesions in lactating dairy cows.
B. O. Omontese*1, R. Bellet-Elias1, A. M. Argüello1, G. D. Catandi1, R. Casagrande1, Z. Rodriguez1, R. S. Bisinotto2, G. Cramer1, 1Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN, 2Department of Large Animal Clinical Sciences, University of Florida, Gainesville, FL.

Lying behavior is a vital indicator of cow welfare and may play significant roles in hoof lesion (HL) development. Objectives were to evaluate the association between lying behavior and HL in lactating dairy cows. Jersey cows (n = 435) without any visible HL were enrolled in early lactation (20 ± 3 DIM; d20), evaluated for body condition score (BCS) and fitted with pedometers (AfiTag II, Afikim, Israel). At mid-lactation (120 ± 3 DIM; d120), cows were reevaluated for the presence of HL and pedometers were removed. Data were analyzed using restricted maximum linear growth mixed measures model with an autoregressive covariance structure. Variables offered to the model included the fixed effects of HL status at d120, DIM, interaction between HL status at d120 and DIM, parity, change in BCS, and calving season. In each model, cow was included as random effect. Lesion status and parity was forced into the final model. Due to data backup failures, only data from 344 cows with a minimum of 6 d of data were used. This resulted in a total of 24,813 d of data were available for analysis. At d120, 56.5% of cows were diagnosed with a HL, of which 88.5% were sole hemorrhage. Fifteen (8.2%) cows were diagnosed with other non-infectious lesions, whereas 8 (4.4%) cows had infectious lesion at d120. Our results show that at enrollment, the cows that developed HL had reduced lying time duration −0.5 h (95% CI: −0.78 to −0.28) compared with cows that remained healthy. This difference in lying time for cows that developed HL gradually became smaller (Coef.: 0.003; 95% CI: 0.002 to 0.005) from early to mid-lactation. Irrespective of lesion status at d120, average lying duration increased progressively from early to mid-lactation. Our results suggest that cow lying behavior is changed before HL development and that the causative mechanism might already have occurred before enrollment in our study.

Key Words: behavior, lying time, lameness