Accuracy of the FeedPhone device for recording eating and rumination times in dairy cows

Several commercially available devices automatically record feeding behaviour of dairy cows on farm, but independent validation studies are often not available. The objective of this study was to determine the accuracy of the FeedPhone® device, developed in France by Medria, to record eating and rumination activities of dairy cows. The FeedPhone is based on a tri-axial accelerometer placed on a collar, data being radio-transferred and processed automatically. The main activity (eating, rumination, or rest) is recorded every 5 min. Validation was performed on 7 lactating dairy cows fed on maize silage and concentrates for a total of 89 full day records. The actual times were determined by a reference method, by recording continuously the weight of the trough and the jaw movements at the minute scale. At the day level, the mean prediction error was 11.5% for eating time and 11.1% for rumination times, with low mean and slope biases (error mainly random). Eating and rumination activities are clearly distinguishable. This precision enables the detection of between-day variations of both eating or rumination times of 20, 10, and 5%, at cow level, small-herd level (4-7 cows) and larger herd level (>20 cows), respectively. This accuracy makes the FeedPhone valuable for studying relative variations of both eating and rumination times of dairy cows fed on total mixed ration