Supplementary data - Virtual fencing technology to intensively graze lactating dairy cattle II: Effects on cow welfare and behavior
Description
Supplementary Tables 1-4 and supplementary Figure 1 ABSTRACT Virtual fencing technology uses a neckband-mounted device to deliver an audio cue when the animal nears a virtual boundary that is set via a global positioning system, followed by an electrical stimulus if it crosses the boundary. The flexibility offered by this technology could revolutionise grazing management on dairy farms, but its application and impacts on lactating dairy cattle have not been assessed. This experiment reports on the effects of an electric or a virtual front-fence on dairy cow behavior and welfare. Two temporally separated treatments were applied to a herd of 30 multi-parous cows. Cows were provided an estimated 14-15 kg DM/cow of fresh pasture in a new paddock every 24 h. From days 1 to 10 cows were grazed using a conventional electric front-fence (control treatment) and from days 14 to 23 they were grazed using a virtual front-fence (eShepherd®). Cows were trained to the technology from days 11 to 13. The milk production and live weight of individual cows were recorded daily. Cortisol concentrations were obtained from milk samples collected from individual cows on 3-days during each of the control and the virtual fence grazing periods, plus the first day of training. From day 6 of the experiment, six focal cows were fitted with a RumiWatch noseband sensor to monitor grazing and ruminating time, and eight focal cows were fitted with an Icetag sensors to monitor activity. Milk production, live weight and the time cows spent standing and lying did not differ between the electric and virtual fence periods. Milk cortisol concentrations, activity and the times spent ruminating and grazing were comparable between the electric and early virtual fence periods (i.e., days 1-3 with a virtual fence). However, at days 4-6 with a virtual fence grazing activity (steps taken and motion index) and time spent grazing were lower, while time spent ruminating was greater, than with an electric fence. Further, LSD tests suggest milk cortisol concentrations were higher at day 5 with a virtual fence than at day 8 with an electric fence and day 1 with a virtual fence. We conclude there is no evidence of behavioral and welfare impacts of virtual fencing on dairy cows in the days immediately following implementation of the technology in a simple intensive grazing regime, but a longer study is required to fully elucidate impacts beyond this period.