On the top deck of a three-tiered structure moored near downtown Rotterdam, brown and white cows graze on hay dropped from a conveyor belt above their heads and rinds of oranges salvaged from supermarket juice machines in the port city. Canopies overhead protect the cows from sun and collect rainwater they will eventually drink. “We call our cows upcycle ladies,” says Minke van Wingerden of the Floating Farm, which sells the milk, cheese and buttermilk produced by the cows in a small shop on dry land next to its harbor berth.