Remote monitoring technologies to understand risk factors for mortality in northern beef cattle

Abstract

One of the biggest economic losses in the northern Australian beef cattle industry is poor reproduction and high mortality. Due to the large-scale of operations, continuous individual animal monitoring is not feasible, and reasons for mortality are largely unknown. The main objective was to utilise remote monitoring technologies to explore factors contributing to mortality. Technologies including walk over weigh (WoW) stations, GNSS collars, vaginal implant transmitters (VIT) and satellite derived vegetation data were used throughout the 4-year trial period to monitor behavioural and physiological factors that may contribute to mortality among the herd. The main findings showed that VIT only gave true birth alerts 27.6% of the time and were not suitable to detect calving events in these conditions. Remote monitoring of behaviour showed that cows travelled longer distances compared to calves on day 1 to 4 after birth, before calves began to travel with their mothers at one week old. The separation between cow and calf in early life could be a risk factor for calf loss because of dehydration, predation, and exposure to heat stress. Predictive modelling showed that satellite imagery, rainfall, and date could be used to predict cow live weight (LW) changes, with a Lin’s Concordance Correlation Coefficient of 0.62 and R² of 0.44. Remote monitoring of LW showed that cow LW loss could be a significant factor affecting survival. Lactating cows at the end of the dry season lost more LW compared to cows that were not lactating at that time of year, and cows that had their calves weaned at the end of the dry season gained more LW compared to cows that did not have their calves weaned prior to the wet season. It is concluded that GNSS devices, satellite imagery and WoW stations could form a suite of remote monitoring technologies with applications refined to manage risk factors of mortality in extensive rangeland beef production.