Nick Seymour was working on a farm when he came across 20 very sick heifers, their water trough bone dry.
"It was traumatic and after that I realised there had to be better ways to monitor troughs," Mr Seymour told AAP.
So he designed the Water Rat, a floating stock water sensor that sends an alert to a farmer's phone when levels are running low.
"Everybody who has livestock for a long period of time has probably had one of those bad experiences or a fright or a scare," Mr Seymour said.
"They understand the reality that water always fails - it's not if it's going to fail, it's when."
The Water Rat is one of many high-tech sensors and remote devices developed by Mr Seymour's ag tech start-up, Farmo, which is based in Victoria.
Farmers in Australia, New Zealand, Canada and the US have adopted the technology to avoid running out of trough water, particularly on large properties.
"Producers love their animals and it's something that everyone wants to avoid, it's a very high priority," Mr Seymour said.
Farmo is part of the inaugural ag tech alley at the Australian National Field Days outside Orange, in central western NSW.
More than 500 companies from across the nation are showing off the latest machinery, technology and farming products at the field days, which are celebrating their 70th year.
Internet connectivity tools, satellite technology, an invasive pest sensor and solar-powered GPS cattle identification ear tags are also on display until Saturday.
A bright blue mobile cattle scale called Optiweigh allows farmers to weigh their livestock in a paddock rather than herding them into yards.
Feed is used to lure the animals onto the scale, which scans their ear tags and sends their weight to a database via satellite.
Farmers can closely monitor changing weights, giving them fast insights into feed quality, livestock health, and sale value.
Optiweigh, based in Armidale, in the NSW New England region, is also working on a model that measures methane emissions.
"The market is saying ... we need a better way to analyse how much we're emitting and whether the practices are improving," support manager Max Laurie said.
Mr Laurie said the wide spectrum of technology available to farmers shows the sector is readily changing.
"It's funny, people think farmers are quite slow to adopt tech, but you've only got to look at how much they've progressed in 20 or 30 years to see that's actually not the case.
"It's just making sure ... it's a solution the farmer wants and knows they need."
