Jessica Roberts

Spatially Enabled Livestock Management: Improving Biomass Utilisation in Rotational Systems

Jessica Roberts
University
University of New England
Supervisor (Academic)
Profs David Lamb, Geoff Hinch, Greg Falzon & Mark Trotter, University of New England
Supervisor (Industry)
Matthew Monk, Sundown Pastoral
Projects
mysite
Employment
Precision Agriculture Scientist at Lincoln Agritech Limited (New Zealand)
Thesis Abstract

There is a call for sustainable intensification of agricultural industries to cope with impending challenges to future food demand and production. Beef and sheep meat production in Australia is dominated by grazing production systems, and equates to the largest land use of the country. Pasture utilisation by livestock can be a major limiting factor in grazing production systems, through under- or over-grazing. This thesis aims to identify if spatio-temporal information from livestock tracking devices can be used to understand livestock-biomass interactions in a rotational grazing system. The specific goal was to determine if this spatio-temporal data might be related to pasture characteristics (particularly biomass quantity) and potentially used as an indicator of the state of the pastures being grazed. Cattle were tracked with GPS for detection and monitoring of specific behaviours including, distance moved, time spent grazing, stationary or travelling, spatial dispersion and social dispersion. Behaviours were compared with declining pasture availability, monitored with
an active optical sensor. This thesis explores the behaviour of cattle in three grazing situations. In all experiments distance moved and grazing time results were considered normal, although behavioural changes observed in relation to pasture biomass did not always follow the same pattern. Large daily variation was observed in most results, potentially problematic for detecting a response to biomass. Considering only how the monitored behaviours relate to biomass, the most appropriate behaviour metrics investigated in this research were time spent grazing or moving and the proportion of the paddock utilised. In most cases these metrics exhibited simple, quadratic relationships with biomass. In combination with real-time monitoring systems these metrics might easily be monitored and key thresholds could be determined, resulting in management trigger points from the steepness of an incline or decline, or occurrence of a maxima or minima. There is potential to continue this research in a commercial context to determine if these behavioural metrics can be related to the pasture
biomass characteristics that are important to producers. If successful, these behaviour metrics could be used to develop an autonomous spatial livestock monitoring (ASLM) systems to assist graziers make decisions that will substantially contribute to the sustainable intensification of red-meat industries across the globe.

The full thesis can be download here.