For decades, we have relied upon visual observation of animal behavior to define clinical disease, assist in breeding selection, and predict growth performance. Limitations of visual monitoring of cattle behavior include training of personnel, subjectivity, and brevity. In addition, extensive time and labor is required to visually monitor behavior in large numbers of animals, and the prey instinct of cattle to disguise abnormal behaviors in the presence of a human evaluator is problematic. More recently, cattle behavior has been quantified objectively and continuously using advanced technologies to assess animal welfare, indicate lameness or disease, and detect estrus in both production and research settings. The current review will summarize three methodologies for quantification of cattle behavior with focus on U.S. beef production systems; 1) three-axis accelerometers that quantify physical behavior, 2) systems that document feeding and watering behavior via radio frequency, and 3) triangulation or global positioning systems to determine location and movement of cattle within a pen or pasture. Furthermore, advances in Wi-Fi and radio frequency technology have allowed many of these systems to operate remotely and in real-time and efforts are underway to develop commercial applications that may allow early detection of respiratory or other cattle diseases in the production environment. Current challenges with commercial application of technology for early disease detection include establishment of an appropriate algorithm to ensure maximum sensitivity and specificity, reliable and repeatable data collection in harsh environments, cost:benefit, and integration with traditional methodology for clinical diagnosis. Advanced technologies have also allowed cattle researchers to determine temporal variance in behavior or variability between experimental treatments. However, these data sets are typically very large and challenges exist regarding statistical analysis and reporting.

Objective—To determine the association of CBC variables and castration status at the time of arrival at a research facility with the risk of development of bovine respiratory disease (BRD). Design—Retrospective cohort study. Animals—1,179 crossbred beef bull (n = 588) and steer (591) calves included in 4 experiments at 2 University of Arkansas research facilities. Procedures—Calves underwent processing and treatments in accordance with the experiment in which they were enrolled. Castration status and values of CBC variables were determined at the time of arrival at the facilities. Calves were monitored to detect signs of BRD during a 42-day period. Results—The areas under the receiving operator characteristic curves for CBC variables with significant contrast test results ranged from 0.51 (neutrophil count) to 0.67 (eosinophil count), indicating they were limited predictors of BRD in calves. The only CBC variables that had significant associations with BRD in calves as determined via multivariable logistic regression analysis were eosinophil and RBC counts. The odds of BRD for bulls were 3.32 times the odds of BRD for steers. Conclusions and Clinical Relevance—Results of this study indicated that low eosinophil and high RBC counts in blood samples may be useful for identification of calves with a high risk for development of BRD. Further research may be warranted to validate these variables for prediction of BRD in calves. Calves that were bulls at the time of arrival had a higher risk of BRD, versus calves that were steers at that time.

Transition of newly received feedlot cattle from a forage- to grain-based diet is challenging, and the appropriate roughage level in receiving diets is debatable. Nutritionists must consider the paradox of dietary transition and roughage level to mitigate ruminal acidosis, yet concomitantly low feed intake presents difficulty in achieving nutrient requirements when metabolic demand is increased due to inherent stress and disease challenge during the receiving period. Previous research suggests that performance is improved at the expense of increased morbidity for newly received cattle consuming diets with less roughage and greater starch concentration. The clinical signs of bovine respiratory disease (BRD) and acute acidosis are analogous; therefore, it is probable that acidotic cattle are incorrectly diagnosed with BRD in both research and production settings. Additional research efforts have attempted to elucidate alterations in microbial populations and digestion, physiological response to inflammatory challenge, and immunological response to infectious bovine rhinotracheitis virus challenge in cattle consuming diets of various roughage levels. Furthermore, our understanding of the rumen microbiome is improving rapidly with culture-independent assays, products such as direct-fed microbials are available, and increased availability and use of fibrous byproduct ingredients requires further attention. Beef cattle nutritionists and producers should consider that the health benefit of receiving diets containing greater levels of roughage and lower energy may not compensate for the reduction in performance compared with feeding receiving diets with lower roughage and greater energy.

Our objective was to explore change in activity variables relative to clinical identification of bovine respiratory disease (BRD) in cattle maintained in a commercial feedlot. Four blocks (n=364) of high-risk, crossbred beef calves were affixed with an accelerometer device upon feedlot arrival that continuously logged activity variables (standing time, step count, lying bouts, motion index) for a 56-day period. Overall, 51.5% of calves were diagnosed at least once with BRD, while 15.2 and 4.5% had a second and a third BRD event, respectively. The level of activity in cases was compared with that of control cohorts relative to the time of BRD diagnosis in cases. Reductions in activity variables in cases started at least 6 days prior to BRD diagnosis, and were more pronounced the day before disease identification. All activity variables were reduced (P?0.01) at day -1 for cases vs controls. Average standing time on the day prior to diagnosis (day -1) was 559 minutes for cases compared to 613 minutes in controls. Step count on day -1 for cases and controls were 843 and 1,472 steps, respectively. The number of lying bouts for cases and controls was 11.4 and 14.5, respectively on day -1. Activity information provided by accelerometers, used as an objective method for identification of BRD in cattle, may assist in management and early detection of sick cattle.