Method: An alternative tool for heart rate data processing in grazing cattle

Heart rate (HR) has proven to be a non-invasive method to assess animal welfare and stress as well as a valuable tool to evaluate several animal traits related to metabolism. Remote sensors have provided the opportunity to monitor this trait individually; nevertheless, this continuous monitoring is prone to measurement errors and thus must be subjected to corrections. Nonetheless, it has proven difficult to establish a general correction method that does not involve a visual examination or does not depend on commercial software related to the measuring sensor. In this sense, this study aimed to develop a simple protocol using R software scripting that could objectively remove erroneous registers from individual 4-day grazing Hereford cattle recordings based on Polar sensors’ data. Using this method, we successfully decreased spurious variation of HR individual records and used this method on other cattle breeds. Nonetheless, calibration could be necessary if the conditions (i.e., other breeds, different physiological states) vary from the ones described in this study.