A Feed Supplement Cuts Methane From Merino Sheep by 43%

Theory and its partners win Textile Exchange’s Collaboration for Global Impact Award for lower-emission wool

Methane from grazing sheep is one of wool’s biggest climate impacts. Theory, owned by Fast Retailing, worked with Australia’s Congi Farm, Sea Forest and Italian mill Botto Giuseppe to test SeaFeed, a supplement given to 2,000 Merino sheep over 120 days.

The award was presented at Textile Exchange’s annual conference in Vancouver.

Inside the pilot:

1. Methane from the sheep’s digestion fell by 43%
2. About 54.5 tonnes of CO₂e emissions were avoided
3. The wool went into Theory’s spring 2026 Regal Wool collection
   

Natural fibres carry a footprint too, and the answers often start on the farm. Pilots like this show how much depends on the people raising the animals and growing the crops. When you buy wool, look for brands that can tell you which farm it came from.