Development of a fenceless livestock control system: Behavioural responses of cattle

摘要

New technology may allow for the development of fenceless livestock control systems (FLCS) to replace traditional fencing. Five studies were conducted using remote Tri-tronicsRTM training units emitting mild electric shock to the muzzle and neck of cattle to control their movements while grazing. The objective of the first study was to determine the most suitable location to deliver an electric shock, as well as the optimum electrical intensity of the shock. The intensity of the shock from a Tri-tronics Sportsman trainerRTM unit attached to a halter affected (P < 0.05) the number of times animals entered the feeding area. The location on the animals' body where the shock was administered (muzzle or neck) (P = 0.18) did not affect control. The objectives of the second and third studies were to identify cues cattle used to establish where the fenceless control system boundaries were located under dry lot and pasture situations. Heifers were fitted with the halters containing the Tri-tronicsRTM training units emitting 5600 V and 32400 ohms by remote control. For 4 d, heifers received a mild electric shock with low ohms and when they approached a boundary within a drylot pen and attempted to go through it heifers were forced to travel around. During the next 4 d the cattle were tested with no boundary in the pen to determine if they could remember it's location. Treatment group and day on test were significant (P < 0.05). Cattle avoided an area with a fenceless boundary without visual cues defining it. In the third study, which was on pasture, heifers appeared to associate the electric stimulus with a widespread area or patch as opposed to a linear boundary. A subsequent study was done to determine if audio and/or visual cues increased the ability of cattle to identify and respond to a FLCS boundary. Attempts to enter the exclusion zone varied among days on test (P < 0.01). The addition of the visual and/or audio cues did not affect the ability of the heifers to detect and avoid the exclusion zone after 3d. Social interactions were evident among herd mates, thus a final study was conducted to determine the influence of dominant animals on herd movements under equipment failure. Although social interactions were evident, adverse stimuli (mild shock) from the FLCS units influenced behaviour more than separation from dominant animals. Heifers with functional units did enter the exclusion area. Herd movement can be controlled with FLCS even if some units fail. (Abstract shortened by UMI.).