The development of a nitrogen sensor for cow urine is hoped to help farmers reach environmental targets for nitrogen run off.
AgResearch has developed the sensor over the past eight years, and is expecting to build a better understanding around how much nitrogen a cow generates.
AgResearch senior scientist Brendon Welten said information from the urine sensors would be a huge help for the sector.
"By understanding the urination pattern we can develop new strategies to mitigate nitrogen leaching losses and this really provides benefits to farmers to meet their environmental targets."
The sensor is attached to the rear of the cow.
"It uses a series of clips which then attach to a ventilated cow cover, and when a cow urinates, the urine will pass through the sensor.
"It uses a pressure and a temperature sensor, and that will give you the urination volume.
"Also contained within the sensor is a refractive index sensor which we use to measure nitrogen concentration."
Dr Welten said it was a very complex tool and required a lot of technical expertise, but they worked well.
AgResearch is testing about 20 cows at a time, and taking measurements over a week long period, he said.
"Typically what we're using them for is to compare feeding levels, for example where we are trying to test different feeds which could reduce the amount of nitrogen in the urine."
The sensors are also being trialled in the UK and Australia.