Method: An accurate method for detecting drinking bouts in dairy cows based on reticulorumen temperature

Abstract

This study evaluated the performances of three methods for detecting drinking bouts in dairy cows using reticulorumen temperature (RT): the ‘FixT’ method based on a fixed RT threshold, the ‘Cow-dT’ method based on a cow-day-specific RT threshold, and the ‘FallST’ method based on RT fall slope. We observed the drinking behaviours of 28 dairy cows equipped with reticulorumenal sensors over 96 h to create a reference dataset. A total of 730 drinking bouts were observed. We matched detected drinking bouts against observed drinking bouts to obtain the number of true-positives, false-negatives, and false-positives, and then calculated the detection performances of the three methods in terms of sensitivity (Se), positive predictive value (PPV), and F-score. The performances of the three RT-based methods (Se ≥ 90%, PPV > 96% and F-score ≥ 93%) were better than those from previous work using collar-attached accelerometers, but slightly lower than methods using drinking troughs connected to electronic identification systems or methods combining accelerometers with geomagnetic sensors or with ultra-wideband location. The FallST method showed slightly better performance (highest F-score) than the FixT and Cow-dT methods. The FallST method accurately detected drinking bouts lasting more than 30 s and at least 30 min apart, with a detection time accuracy of 10 min. The models using RT curve parameters failed to predict characteristics of the drinking bouts. In conclusion, the method developed here can accurately detect drinking bouts in dairy cows using RT, but without further characterisation of the drinking bouts (e.g. duration).