Can virtual fences be used to control grazing sheep? M. Jouven A,B,D , H. Leroy B , A. Ickowicz C and P. Lapeyronie A,B A SupAgro, UMR SELMET, 2 Place Pierre Viala, F-34060 Montpellier, France. B INRA, UMR 868 SELMET, 2 Place Pierre Viala, F-34060 Montpellier, France. C CIRAD, UMR 112 SELMET, 2 Place Pierre Viala, F-34060 Montpellier, France. D Corresponding author. Email: jouven@supagro.inra.fr Abstract. Virtual fences (VF) are based on sensory cues delivered to domestic animals with the aim of controlling their spatial behaviour without any physical barrier. VF represent an approach for controlling the distribution of free-ranging large herbivores in large rangeland areas where the implementation of human control or the use of physical fencing is made impossible by their cost, environmental concerns or specific regulations. The potential of using VF for sheep was investigated by studying the spatial behaviour of groups of 5 or 32 ewes submitted to a commercial animal-borne VF device aimed at containing them in a defined area in a series of experiments. All tests were performed in pasture alleys virtually divided in their centre by a 4-m-wide warning/punishment zone). The ewes were introduced on one side of the zone, the other side being made attractive by the presence of tall grass (feed attractant), the presence of peers (social attractant) or being made unattractive by the presence of short grass (same feed as in the alley). In a first experiment, ewes were trained in groups of 5 with a feed attractant, following a 3-stage procedure: 30-min adaptation, 90-min training with a visual cue (three white strings above the wire of the VF) and 30-min test without a visual cue. In a second experiment, the test stage was repeated for each group with feed, social and zero attractants. In a third experiment, the test with feed attractant was performed with groups of 32 ewes comprising previously trained and equipped ewes mixed in different percentages of trained: naïve (untrained and unequipped) ewes (100 : 0, 75 : 25, 50 : 50 and 0 : 100%). One year later, this test was repeated with a feed attractant either close (30 m) or far (60 m) from the punishment zone. By increasing the distance to the feed attractant, it was anticipated that this would stimulate the conflict of motivation between feed and peers. Ewes learned readily the concept of VF after a couple of contacts with the punishment zone. In the second experiment in the test with a social attractant, a few trained ewes penetrated the VF to re-associate with peers located in the pen opposite the VF. Expression of the behaviour to challenge or cross the punishment zone differed widely among individuals. In mixed groups, naïve ewes crossed the punishment zone and lead part of their trained peers across the punishment zone, regardless of the distance of the feed attractant from the punishment zone. The results suggest that VF can be used to alter the distribution of grazing sheep within large fenced areas although they cannot replace conventional fences for absolute control. Additional keywords: conditioned stimulus, grazing management, social attraction, virtual fencing. Received 29 July 2011, accepted 9 January 2012, published online 29 February 2012 Introduction Rangelands are an important forage resource for many extensive farming systems worldwide. Their utilisation involves ecological issues, such as natural habitats and biodiversity preservation, but also relates to technical issues, such as forage self-sufficiency or labour efficiency, and to social issues such as the sustainable use of rangelands. Grazing management plays a major role in reconciling these sometimes conflicting issues by choosing the season of utilisation, grazing intensity, stocking density and by influencing grazing distribution through human control, fences or focal points such as water, shelter or salt (Bailey 2004). Automated devices are promising tools to minimise human intervention in grazing management, where it is not economically sustainable, or to refine grazing management in free-ranging systems (Jouven et al. 2010a). A virtual fence (VF) can be broadly defined as ‘a structure serving as an enclosure, a barrier or a boundary, without a physical barrier’ (Umstatter 2011). Three categories of VF approaches are described in the recent review of Umstatter (2011): (1) to contain animals in a given area using animal-borne devices, (2) to contain animals using external devices near the VF line, and (3) to gather animals or keep them apart from each other with moving VF lines. In this study, we considered the first approach, where the basic principle is to fit the animals with a special collar which delivers a message (stimulus) and a punishment (electric shock) when the animal approaches the Journal compilation Ó Australian Rangeland Society 2012 www.publish.csiro.au/journals/trj CSIRO PUBLISHING The Rangeland Journal, 2012, 34, 111–123 http://dx.doi.org/10.1071/RJ11044