Using temperature-sensing reticular boluses to aid in the detection of production diseases in dairy cows

The objective of this study was to investigate associations between increases in reticular temperature (RT) in dairy cows and the diagnosis of metritis, mastitis, lameness, and pneumonia by dairy personnel. A prospective case-control study was conducted on a 2,175-cow dairy operation in Colorado from May 2010 to April 2011. Each cow received an orally administered temperature sensing reticular bolus after parturition and RT measurements were recorded 3 times per day as lactating cows exited the milking parlor. A cow was identified as having an increased RT when a deviation of 0.8°C above baseline (average of readings of previous 10 d) was recorded by the TempTrack software (DVM Systems, LLC, Greeley, CO). During the same study period, dairy personnel without access to RT data recorded health events and classified them according to clinical signs observed. A total of 201 health events (cases) were included in the data analysis. Cows with clinical mastitis and pneumonia had significantly higher odds (6.7 and 7.5 times higher, respectively) of having an increased RT of 0.8°C above their baseline within 4 d preceding diagnosis when compared with control cows. Specificity and sensitivity for an increase of 0.8°C above baseline RT within 4 d of disease diagnosis was 76.85 and 66.97% for mastitis, and 69.23 and 76.92% for pneumonia, respectively. No significant difference in RT was found for cows diagnosed with lameness or metritis. Results of this study suggest that RT monitoring can be a useful tool in the early detection of mastitis and pneumonia in dairy cows.