The merino meat brand would initially be sold internationally through top-end restaurants, starting in New Zealand, with potential also for high-quality food stores.
"This is about creating the brand, telling the story, the whole marketing pitch," he said.
The merino sheep will go to slaughter at about 18 months, compared with lambs which are generally considered to be under 1 year old and mutton which was 4 to 5 years old.
The companies had proved that somewhat older sheep had a better developed taste and with tenderness, Cooper said.
"We were challenging the norms and saying, well, is this really that smart when farmers need a sustainable revenue source and yet there were some old rules that said we had to slaughter lambs by virtually October, November each year when their teeth erupt so we comply with an old-fashioned market."
NZ Merino Company chief executive John Brakenridge said demand from customers meant they were running out of wool.
"This is another mechanism for being able to generate more wool by taking an animal through for an older age," Brakenridge said. "There's more wool, there's more meat because they're a bigger animal and there is a better story associated with it and therefore you can get more money."
As a rough guide the joint venture, Alpine Origin Merino, was aiming to take the combined value of merino wool and meat from about $150 million a year to a potential $230 million during the next five years.
There were about three million merino sheep in the national flock and about 800,000 were sent to slaughter each year, of which the joint venture was aiming for 500,000 annually during probably the next three to five years.
Farmers would get three-year contracts, as with wool, and would contribute 4 per cent of the value of the animal towards market initiatives.
Cooper said there were growth opportunities for merino co-products such as pelts, nutraceuticals and lanolin.