Validation and inter-device reliability of a behavior monitoring collar to measure rumination, feeding activity, and idle time of lactating dairy cows

Interdevice precision and accuracy are not investigated for precision livestock farming (PLF) technologies, but are fundamental for the use of data in populational metrics and to compare cows' data. This study aimed to validate a behavior monitoring collar (BMC; CowMed, Santa Maria, RS, Brazil) and its interdevice reliability. First, we compared observations with the BMC, and second the interdevice precision and accuracy for rumination, feeding activity, and idle time of lactating dairy cows. Holstein cows (n = 23) were housed in a voluntary milk system freestall barn and fitted with 2 devices within the same cow. Observations were made over 2 periods of one day (0700 to 1100 h, 1400 to 1700 h); the 7 h per cow were summarized for each behavior to assess the agreement of observed behavior and BMC data. To assess the interdevice reliability, 26 d of BMC data were summarized by day per cow for both devices. Pearson correlation (r), coefficient of determination (R