The effects of global navigation satellite system (GNSS) collars on cattle (Bos taurus) behaviour

The use of Global Navigation Satellite System (GNSS) collars has become an increasingly important research tool to study the behaviour of domestic livestock species in grazing conditions. However, relatively little is known about the effects on livestock behaviour of livestock “wearing” such collars. The aims of the present research were to determine if GNSS collars affect the behaviour of beef cattle at pasture, and whether an habituation period is required before the animal is accustomed to wearing the device. Behaviour observations were conducted on 20 Charolais cows which were maintained as a single herd in an 8.9 ha paddock. Behaviour was recorded during 13 of 15 days using a scan sampling technique every 5 min for a total of 8 h daily. The trial was divided into three, 5-d periods: before, with and after wearing GNSS collars. During the “with collar” period, 10 randomly selected cows were fitted with a GNSS collar (CD cows) weighing 0.61 kg (0.1% of liveweight) whereas the remaining 10 cows were not fitted with GNSS collars (NC cows). Over the course of the 15 days, 12 mutually exclusive behaviours were recorded for all cows: stand stationary, graze, walk, run, drink, stand ruminate, lie ruminate, rest/idle, social, self-directed, other and out of view. No significant behavioural differences were found between CD and NC cows, with the exception of stand stationary which was greater in CD (9.7%) than NC cows (7.3%). However, there was no interaction with Collar by Period, Day and Hour for any behaviours. During the first hour during the “with collar” period there was no significant effect on behaviour between CD and NC cows when behaviour:hour of day combinations were analysed. Therefore, it would appear that the presence of GNSS collars did not modify any cow behaviours with the exception of stand stationary over the course of this trial, and for future trials an habituation period to the collars is not necessary. This knowledge validates the use of GNSS technology for studying cattle grazing behaviour, and is thus important for future research involving the application of these remote sensing devices to study livestock behaviour.