The eco guide to grass-fed

Using products from livestock reared on grass as opposed to grain improves the lives of farm animals - and it has health benefits, too

'Grass-fed" is the new organic. It appeared on Whole Foods' new trend list, with "heirloom ingredients" and "ancient grains". US sales of grass-fed labelled milk, eggs, yogurt, butter, cheese and even protein powders are soaring.

The attraction is that livestock are reared outside, deriving most of their diet from grass. This is in contrast to the North American system where cows are grain-fed in a Cafo (concentrated animal feeding operation), with scant access to pasture.