Training Maremmana heifers to virtual fencing management: preliminary results

Virtual Fencing (VF) is an innovative technology based on GPS collars. VF allows to set the virtual grazing area limits and when the animals approach the fences, they receive an audio cue followed by a low electrical pulse, if animals cross over the fences. The study aimed to test the feasibility of using VF in an agrosilvopastoral system to facilitate the management of 22 Maremmana heifers reared in a pilot farm in Maremma (southern Tuscany, Italy). To this, a training trial was carried out to test the reaction of heifers to this innovative managing tool. The testing activity was carried out within a 1.5 ha physically fenced paddock. It lasted 60 days in total and it was divided into 4 phases, during which the data recorded by collars were collected (S=number of sounds, Z=number of electrical pulses, Z/S=ratio, and animal position) every 15 minutes. For 5 days (T0), virtual boundaries were set coincident to the physical ones as to allow the animals to adapt in wearing the VF collars, then 1/3 (T1, 14 days) and 1/2 (T2, 14 days) were excluded of the paddock by reshaping the virtual boarder. After 14 days the area available for grazing was shift to the other half (T3), and animal were excluded from the previous one. Data were analysed by ANOVA using SAS’s GLM procedure. S was significantly lower in T1 (14.46) than in T2 (27.16). Z did not show significant differences between the training phases, only a decreasing trend was identified from T1 (3.30) to T3 (2.60). The Z/S ratio, instead, decreased in T2 and T3 with respect to T1, as the S increased and Z decreased in the last phases. Escapes recordings were limited to few animals in the herd during the first hours of each VF change. Aggregate animals’ positions for the T1, T2, and T3 showed that every time animals used all the area available, even some hours from the beginning of each phase were needed to start exploring the zones previously excluded