GPS technology as a tool to aid pasture management on dairy farms


  • Wayne Hofmann DairyNZ
  • Mark Neal
  • Siimon Woodward
  • Tania ONeill



This research determined the accuracy and precision of Global Positioning System (GPS) enabled devices as a potential tool to automate the recording of onfarm grazing events, which can be used to indicate productivity of paddocks (with number of grazings per year), or, when combined with other farm data, estimate nergy harvested. Static tests were initially conducted to determine the devices’ accuracy (location error) and precision (Circular Error Probability; CEP). Based on 11 Agtech and 22 mOOvement devices tested, the mean location error was 5.4 m and 34.2 m, respectively. The 95% CEP was 13.9 m and 77.6 m, respectively. In the subsequent on-farm study, 11 cows in a 400- cow milking herd were fitted with an Agtech and mOOvement ear tag and two with digitanimal collars. Data were analysed for the AM and PM grazing periods for four days. The digitanimal collars recorded 62.3% of total observations in the correct paddock, instead of adjacent paddocks or races, compared with 52.5% for the Agtech devices and 45.2% for the mOOvement ear tags. These results suggested that GPS technology is
feasible for the automated recording of grazing events. However, a longer-term study is required to demonstrate the value this technology could have for farmers.


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How to Cite

Hofmann, W., Neal, M., Woodward, S., & ONeill, T. (2023). GPS technology as a tool to aid pasture management on dairy farms. Journal of New Zealand Grasslands, 84, 189–196.



Research article


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