For the past two years, the Gore farmers have supplied the Marks and Spencer United Kingdom supermarket chain.
The contract requires exacting performance and management, but the couple say it has proven rewarding both financially and professionally.
The Crawfords were the inaugural winners of the Alan McRae Memorial award, run by Rissington Breedline, which recognised them as the country's premier supplier of lamb to the firm's Marks and Spencer (M&S) contract.
Suppliers were assessed on meeting the grade and quality specification with 80% of their lambs, their farm-quality assurance programme and a farm-productivity analysis to ensure meeting those specifications had not compromised the rest of their business.
Mr Crawford said the shift to the supply contract started in 2003 when they moved from a Coopworth ewe flock to Highlanders - a composite cross between Romney, Finn and Texels developed by Rissington.
These were crossed with a Primera terminal sire and Mr Crawford said the effect was immediate, the 2007 lambing having been the best ever at 160%.
This year, the 4000-ewe flock has scanned 192%.
Last season, they contracted 3000 lambs to M&S through Rissington Breedline logistics and marketing, now part of Silver Fern Farms.
They had a minimum target carcass weight of 19kg but achieved an average of 19.5kg and also finished another 1338 lambs outside the contract.
In February, they were selling 300 prime lambs a week.
Mrs Crawford said the goal of the contract was to show leadership and "to be on the front foot".
But to do so while also meeting the M&S standards meant monitoring their carbon footprint and greenhouse gas emissions, land management, having environmental and quality assurance plans, animal welfare and food safety plans, and an objective for their business; and recording their community involvement.
Mrs Crawford said in practice that meant recording much of what they already did, but in the case of meeting the requirements of an environmental plan, it meant testing water in creeks flowing through their farm to ensure they were not affecting quality, and having a waste-management plan.
For this, they received a premium price for their lamb and the possibility of their names appearing on M&S packets of meat produced from their farm.
Their prize for being the premier supplier of lamb for the contract was a trip to the UK to follow the path their meat took to the supermarkets, including a look at M&S' operation.
There, they saw meat on sale labelled as coming from Alistair Hogg from the Manawatu and Simon McRae from Southland.
"Their commitment to quality, investment to packaging and processing was impressive," Mrs Crawford said of M&S.
The trip gave them an insight into the thinking of consumers and retailers, but more importantly what they expected of their suppliers and that farmers needed to think beyond their farm gate.
She said M&S had an EcoPlan which was the basis of every aspect of the business.
M&S was committed to tackling environmental and social concerns such as climate change, waste minimisation, sourcing sustainable raw materials, the health of the products it sold and its consumers, and being fair with its business partners.
The Crawfords were told that by 2012, all of M&S' 600 stores planned to be carbon neutral with no waste sent to landfills.
The supermarket giant was also introducing a database for all its protein suppliers through which checks can be made on how well standards were being maintained and compliance met.
Mrs Crawford said the couple came home aware UK supermarkets and consumers wanted New Zealand lamb, but to get access to its affluent customers, farmers had to meet criteria and standards.
They have also returned with an appreciation that supermarkets like M&S wanted lamb of a consistent quality all year round.
It has reignited their enthusiasm about the prospects and potential for the lamb trade, and they are trialling a 6ha chicory and red clover specialist lamb-finishing crop.
From January to May, it grew 10 tonnes of dry matter a hectare, and early signs were that lamb yields increased.
The Crawfords work closely with a crop-farming neighbour and have an arrangement where they exchange the use of similar sized areas of land, which has accelerated the pasture renewal process.
M&S contracts were a priority for their business, she said.