Cows prefer Beethoven to the Beatles. But that doesn't mean they're highbrows--they're just relaxed by a soothing beat, claim psychologists at the University of Leicester in the United Kingdom, who say that exposing bovines to slow music increases milk yields.
Music researchers Adrian North and Liam MacKenzie tested the effects of music on 1000 Holstein cattle at two dairies. They piped in either fast (more than 120 beats per minute), slow (less than 100 beats per minute), or no music from 5 a.m. to 5 p.m. every day for 9 weeks.
The result? Cows that heard music such as Beethoven's "Pastoral Symphony" or Simon and Garfunkel's "Bridge Over Troubled Water" gave 3% more milk than the ones that heard no music. Fast, screechy music such as Bananarama's "Venus" seemed to cause a small decrease in production, they found in a yet-unpublished study.
"We believe that slow music relaxes the animals as it does humans," says North. The researchers now want to test their hypothesis by directly measuring how different musical diets affect levels of stress hormones in cows.
Animal welfare specialist Lene Munksgaard of the Danish Institute for Agricultural Sciences at Foulum notes that a 1989 study also indicated that classical music was more conducive to milk production than noise such as traffic sounds. But while acute stress will lower immediate milk yield, she says, "whether the observed effect can be attributed to decreasing chronic stress is speculation."