The chain said the footprinting initiative had proved a big success in the dairy sector and had removed more than 5,000t of CO2 from its milk supply chain in the past year.
Annie Graham, Sainsbury's head of brand sustainability, said: "Dairy farmers who took part in the project have responded extremely positively, reporting significant cost savings as well as increased efficiency and environmental improvements."
She claimed Sainsbury's was the only retailer taking the time to visit each individual farm to assess ways it could be working more environmentally. She said the scheme was not just about improving the environment, but about increasing efficiency within the supply chain.
Judith Batchelor, director of brand, said Sainsbury's saw sustainability as being underpinned by three things: environmental, economic and social. "When we talk about sustainability, we're talking about these three things."
She said Sainsbury's was not going to start putting food miles on its labels as a shorthand for sustainability, as the subject was far more complicated than that.
She added that the subject of sustainability was still in its infancy and the retailer was still getting to grips with the concept. "We're on a learning curve and we're learning quicker than ever before about this thing. What that means is that what we know in two years will be very different to what we know now."
As a result, she said that meant the chain had to be careful on how it communicates with customers on sustainable issues.
Being sustainable would also mean having to make trade-offs, she warned. "Those trade-offs may well have to be judgement calls as well – for example what is more important, animal welfare or water, or carbon and water."