Livestock producers are increasingly adopting various on animal sensing technologies. One of the biggest questions when doing so, is just how many devices are needed to effectively monitor a group of animals? This is a crucial question when one considers that these wearable IoT devices or "smart tags" are often somewhat expensive on an Individual animal basis. Reducing the tag coverage per animal to anything less than 1 should be explored, as it of course reduces the costs of deployment for any type of production system, but what happens to the anticipated benefits? Do they scale at a similar rate?
'Sentinel Animal Monitoring' - What is it?
At its most basic, this reduced coverage approach, or "sentinel monitoring", simply means tagging just a proportion of the animals in a mob or herd. The goal being that this reduced sample of animals is actually providing a good average or benchmark of the remainder of the herd or mob. CQUniversity's Associate Professor Mark Trotter explains further,
"You don’t have to tag every animal to get value. You can save money and still have very valuable data coming in. It’s the same for the timeliness of the data, for some applications you don’t need real time location, a location every few hours or so is plenty."
How do I get the most out of the tags?
One of the big questions with this model relates to how the benefits change with the reduction in tag numbers.
"If money was no object, sure tag everything, but cost has to be factored in. Also, every property has a different application, many of which can be achieved using sentinel monitoring, like stock theft, while other producers interested in detecting calving events, require all cows to be tagged. Other financially sensible applications involve tagging high value animals like bulls which could also be tagged at a 100% rate"
Marks work in this area can be explored further in a full report published by Meat and Livestock Australia. One of the big upsides of this sentinel monitoring approach is that these benefits will potentially be achievable at a much lower costs and in a time frame sooner than when whole of herd tracking might be achieved.
Let's take a look at this strategy on-farm...
2,000 kilometres west of Mark and CQU lies Aileron Station, 1 million plus acres of central Australian grazing country. Craig & Sarah Cooke are the managers at Aileron and have first hand experience with sentinel monitoring.
"We have currently tagged 31 head out of a mob of 145 animals. We are working our way up to tagging around 300 of the 4000 animals on the property, ideally we will stay around a 8-10% tagging rate".
Craig goes on to explain how this figure was derived
"Most of it was by feel and testing as we went until we believed we were getting an accurate picture of what the animals were doing".
The team at Aileron are focused on monitoring animal movements, patterns and achieving mustering efficiencies,
"We need to keep a close eye on cattle, now made possible by the tags, to understand for example how long a paddock is good for. If we start to see animals ranging further and further away from the water, we know they need to be moved to a location with better access to feed".
The Aileron story is being repeated on farms in over 17 countries around the world today, sentinel monitoring has a place In almost every type of production system and geography.
Sentinel monitoring is a very powerful approach that can be adopted by almost any producer. The key to making this strategy successful Is to understand what 2 or 3 key use cases you are going to go after and then only deploying enough tags to achieve that. Commonly we are seeing this land in the 5-15% range of animals being tagged, with a notable exception being bulls which are routinely tagged at 100% coverage.