An AgResearch scientist has developed a non-invasive pain-free way of assessing whether cattle are suffering from stress or pain.
The process, which was first used on deer, uses an infrared camera to measure the animal's eye temperatures, which change when the animal is under stress or pain.
Mairi Stewart helped develop the method while studying for her PhD at Massey University.
She said the researchers gave the animals different levels of pain relief, and used the hand-held camera to measure eye temperature during routine farm practices such as removing the buds of undeveloped horns on calves, as well as castration.
Dr Stewart said the infrared technology has some advantages over other ways of measuring pain, such as taking blood samples for adrenalin, as the injection itself can cause a stress response.
She said the tool is likely to be useful to researchers and vets, especially when looking at the effectiveness of drugs.
Another aim of the research was to show farmers that anaesthetic should be used during painful procedures.
Dr Stewart says although the technology has so far been used only on cattle and deer, it could probably also be applied to other animals such as sheep.
The research has been recognised with a KuDOs award for emerging scientists from the Hamilton Science Award Trust.