The outdoor life - should racehorses be turned out?
Three million years ago, various species of the genus Equus existed across North America, Europe and Asia. Predominantly animals of the steppes and plains, they made attractive targets for the human hunters who shared these harsh regions. Eventually, some 6,000 years ago in the Ukraine, the relationship was changed from hunter/prey to herdsman/livestock.
Barry Sangster & Phil Dyson (European Trainer - issue 28 - Winter 2009)