LAUSR

Simple Summary Intensive farm conditions have an impact on welfare and can reduce the locomotor behavior of calves. The Actiwatch-Mini® (Cambridge Neurotechnology Ltd., Cambridg, UK), an actigraphy-based data logger was used to record the total locomotor behavior of 30-day-old calves, which showed diurnal daily rhythmicity. An individual daily rhythm of total locomotor behavior has also been found and varied in the same subject from day to day, and from subject to subject, and these variabilities need to be taken into account during the farm monitoring. Abstract Housing confinement, adaptation to different light/dark conditions, and social deprivation could modify the amount of total locomotor behavior of calves recommended for their psychophysical health. Total locomotor behavior was recorded by means of an activity data logger every 5 min for 6 consecutive days. To do that eight clinically healthy 30-day-old Holstein calves living in calf boxes under natural photoperiod and environmental conditions were enrolled. ANOVA (analysis of variance) showed a statistical effect of the day of monitoring and animal. In the temporal distribution of the resting–activity frequency, it was observed that the calves presented periods of total locomotor behavior with the existence of two peaks, one between 06:00–07:00 and another between 17:00–18:00, which corresponds to time of food intake. In all animals, a diurnal daily rhythm of total locomotor behavior was observed during time of monitoring. Intrasubject and intersubject variabilities were statistically different in mesor, amplitude, and robustness of rhythm. In conclusion, the total locomotor behavior showed a diurnal daily rhythmicity in 30-day-old calves. The characteristics of rhythm were different from individual to individual and from day to day. The recorded intersubject variability must be taken in consideration during the monitoring of farm animals and justifies the application of the device to each animal, as precision livestock farming suggests.