Auteur: Allain C., Raynal J., Beck C., Delagarde R. and Brocard V.
Jaar van uitgifte: 2015
The Lifecorder+® is a uniaxial neck-mounted activitymeter. It was tested to assess grazing time in two French experimental automatic milking system farms (20 cows equipped on the Derval farm, 14 cows equipped on the Trévarez farm). The Lifecorder+ raw signal (from 0 to 9) was converted into a grazing yes/no information over a certain threshold. The data from the sensors were compared with visual observations as reference: trained observers recorded activity with a scanning every 10 minutes in the pastures. The recorded activities were as follows: grazing/ruminating and standing/lying/walking. Observation sessions were performed on the Derval and Trévarez farms. Finally, 20 recordings were available for the Derval farm (121 h of cumulated observation time in pasture) and 91 for the Trévarez farm (336 h of cumulated observation time in pasture). The results show a high correlation of grazing time between the visual observations of activity and the information from the sensor (R2=0.93 on the Derval farm and 0.82 on the Trévarez farm) with a mean prediction error of 18 min (9%) for the Derval farm and 29 min (20%) for the Trévarez farm. Some slight biases related to the recording of walking in the pathways were noticed. Lifecorder+ appears to be a possible cheap, easy and precise tool to record grazing time at pasture.