Will smart sensors give sheep a voice?

Sheep farmers have always relied on stock sense: knowing when animals are thriving and when something is just not right.

New research suggests that technology may soon help sharpen that instinct, giving sheep a quiet but constant way to ‘tell’ farmers how they are coping in real time.

A major New Zealand review published in the New Zealand Journal of Agricultural Research brings together the latest local work on sensor technology and sheep welfare.

Led by AgResearch scientist Karin Schütz and colleagues, the paper looks at how small wearable sensors can monitor behaviour and physiology in extensively farmed sheep, with the aim of spotting problems earlier and improving both welfare and productivity.

At the heart of the research is the idea that behaviour changes first.

Before sheep show obvious signs of illness, they often graze less, lie down more, move differently, or alter their daily routines.

On large farms, those subtle changes can be hard to see, particularly when mobs are spread across big paddocks.

Sensors offer a way to keep an eye on individual animals without extra labour or handling.

Much of the work has focused on accelerometers, small devices that measure movement.

Fitted to collars, legs or ear tags, they can accurately identify common behaviours such as grazing, ruminating, standing and lying.

NZ trials have shown accuracies above 80 per cent, which is good enough to build reliable pictures of how sheep are spending their day and night.

This matters because behaviour patterns can act as early warning signs.

In parasite studies, lambs challenged with internal worms showed clear changes well before they looked unwell.

They spent less time feeding and more time lying down as the parasite burden increased.

That kind of information could help farmers intervene earlier and more selectively, rather than relying on blanket treatments across the whole mob.

There are also promising findings around facial eczema, a disease that costs the industry hundreds of millions of dollars each year.

Researchers found that accelerometers could detect repeated head-shaking behaviour, which has long been associated with discomfort during high spore periods.

While the technology is still being refined, it raises the possibility of earlier alerts when risk is rising.

Heat stress is another growing concern, particularly as summers become warmer.

Sheep under heat load can breathe extremely fast, making respiration rate difficult to measure by eye.

New trials using acoustic sensors show that breathing rate can be recorded accurately by sound alone.

These lightweight sensors could eventually be built into collars, providing farmers with real-time information to help manage shade, water and grazing during hot conditions.

Sensor technology is also shedding light on lambing behaviour.

GPS collars have been used to track ewe movement before, during and after lambing.

Changes in movement patterns can indicate when lambing has occurred, and early work suggests that post-lambing behaviour may be linked to lamb growth rates.

While GPS systems still face challenges such as battery life and durability, the research shows clear potential.

The authors are careful to point out that technology must be practical to succeed on sheep farms.

Devices need to be robust, affordable, easy to fit and comfortable for animals.

Data must be accurate and simple, delivering clear signals rather than overwhelming farmers with numbers.

Sheep systems also differ from dairy, with less infrastructure, fewer daily checks and large flock sizes, so tools need to be designed with those realities in mind.

While most sensor technology for sheep is still under development, progress is rapid.

Costs are coming down, accuracy is improving, and systems are becoming easier to use.

The research shows that sheep behaviour can be measured reliably and linked to real welfare and production outcomes.

The message from the science is clear.

By listening more closely to what sheep behaviour is telling us, farmers could act earlier, target treatments better, reduce losses and improve animal wellbeing.

Sensors won’t replace good stockmanship, but they may soon become another useful tool in the kit - helping sheep speak up before small problems turn into big ones.