Activity behaviors and relative changes in activity patterns recorded by precision technology were associated with diarrhea status in individually housed calves

Abstract

The objective of this case-control study was to quantify if there was an association of daily activity behaviors and relative changes in activity patterns (lying time, lying bouts, step count, activity index) with diarrhea status in preweaned dairy calves. Individually housed calves sourced from auction were health scored daily for signs of diarrhea (fecal consistency loose or watery for 2 consecutive d) for the 28 d after arrival. Calves with diarrhea were pair matched to healthy controls (n = 13 matched by arrival date, arrival weight, and diagnosis d to diarrheic calves). Mixed linear regression models were used to evaluate the association of diarrhea status, and the diarrhea status by day interaction with activity behaviors (d -3 to d 4) and relative changes in activity patterns (d -3 to d 4) relative to diagnosis of a diarrhea bout. The serum Brix % at arrival and daily THI from the calf barn were explored as quantitative covariates, with d as a repeated measure. The baseline for relative changes in activity patterns was set at 100% on d 0. Diarrheic calves were less active; they averaged less steps (119.1 ± 18.81 steps/d) than healthy calves (227.4 ± 18.81 steps/d, LSM ± SEM). Diarrheic calves also averaged lower activity indices (827.34 ± 93.092 daily index) than healthy calves (1396.32 ± 93.092 daily index). There was also a diarrhea status by day interaction for lying time on d -3, with diarrheic calves spending more time lying (20.80 ± 0.300 h/d) than healthy calves (19.25 ± 0.300 h/d). For relative changes in activity patterns, there was a diarrhea status by day interaction on d -2, where diarrheic calves had greater relative changes in step counts (diarrhea 634.85 ± 87.581% vs. healthy 216.51 ± 87.581%) and activity index (diarrhea 316.83 ± 35.692% vs. healthy 150.68 ± 35.692%). Lying bouts were not associated with diarrhea status. These results show that diarrheic calves were more lethargic, and they had relative changes in activity patterns -2 d before clinical signs of diarrhea. Future research should explore the potential of an activity alert which positively indicates an individually housed calf at-risk for a diarrhea bout using deviations from relative changes in individual calf activity patterns.