How do you know when a farm animal is unhappy? Animal welfare researchers wish they had easy ways to measure malaise in pigs, or stress in cows. But those tools are lacking—which is why scientists in Australia studied sheep they’d dosed with Valium.
“Animals are not able to talk to express their emotions,” says Caroline Lee, an animal welfare scientist at CSIRO in New South Wales. “We need to use other ways of understanding how they are feeling.”
One such way is to look for changes in