accelerometer

Bijeenkomst: EGF2015
Auteur: Allain C., Raynal J., Beck C., Delagarde R. and Brocard V.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
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.

Bijeenkomst: EGF2015
Auteur: Delagarde R. and Lemonnier J.P.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
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.