| Virtual fencing (vf) is a GPS-enabled fencing technology that replaces the visual cue of a physical fence with an acoustic signal and an optional electric pulse and therefore allows the grazing of livestock in areas that are environmentally sensitive, protected, or difficult to access. So far, research and commercial trade have concentrated mainly on cattle, but the Norwegian system ‘Nofence’ is also available for sheep and goats. In this study, two groups of 10 adult ‘Blobe’ goats wearing Nofence-collars with offspring were successively trained to vf. In the first two days of the 12-day schedule, the vf line was marked by a physical fence, which was gradually removed. On day eight, the vf line was shifted to enlarge the accessible grazing area. An evaluation of acoustic signals and electric pulses showed a higher number of acoustic signals than electric pulses, which implies that goats were responding to the acoustic signal alone, thus avoiding the electric pulse. After shifting the fence line, the number of acoustic signals and electric pulses increased as the goats explored and tested the new boundary. All goats with Nofence-collars – with two exceptions – remained within the virtual fence and no escape registered by the system occurred. The increase in the success ratio indicates that the animals are learning, which corresponds to the data from experiments with sheep and cattle.
The first results of the HF measurements showed clear effects of the electrical impulse on the heart rate and the regularity of the pulse. The evaluation of the goats’ basic behaviors through interval observation did not reveal any clear, directed differences. The measurement of cortisol metabolites in the feces as a stress indicator and the weight gain during the experimental period gave comparable results in the respective vf and pf groups. Using the FCM, no clear negative effect of the vf system could be demonstrated, which is consistent with the literature. Overall, this study can serve as a basis for further studies with virtually fenced goats. Further developed experimental designs with increased animal contact with the virtual fence can help to gain more insight into the potential of vf technology as a pasture management tool for goats. |