The cow whisperer

By Silvia Sanides

Feature: What's in your milk?

Slideshow: From feed to bottle

Milk: It's electric

Dairy economics: Milking blood from a stone

Milk and human health: What's the state of the evidence linking milk to human disease?

Infographic: What's in your milk? A selected list of hormones, growth factors and other substances found in an 8-ounce glass of milk.

Peter-Christian Sch?n is an engineer with a heart - and an ear - for animals. While a postdoc at the Research Institute for the Biology of Farm Animals in Dummerstorf, Germany, his job was to automate animal care by making it possible to clean stables and feed their occupants with the push of a button.

After spending lots of time in the stable, however, Sch?n was distracted by the sounds animals make, and soon shifted his focus towards the conversations they have with one another. "They communicate much more than ...