Watch: Aussie farmer's heartbreaking plight

"This is a video I hoped I'd never have to film," Casey Treloar wrote when she posted this video to Facebook.

The South Australian agricultural journalist and third-generation dairy farmer's heartfelt clip about having to sell the family dairy farm has since gone viral on social media, clocking more than 700,000 views on Facebook with hundreds of thousands more on Twitter.

"The clock has run out and it's time to say goodbye."

Treloar, whose family farm is an hour out of Adelaide, says the heartbreaking decision that prompted her video came after a family discussion.

Listen to the interview below:

"It's a decision we've had to toy with for the last 10 years. We knew it was a matter of when, not if," she told Jamie Mackay on The Country.

She said it was spurred by the devalation of Australian milk in 2011.

As Mackay put it to her: "You're going to have to sell the family farm because you can't make a buck because the supermarkets are screwing the cow cockies."

Treloar said in her video the industry was in this state because of the $1 a litre milk which was introduced in 2011, which devalued their product."

She told Mackay her plea was for customers to support local brands rather than cut-price milk.

And she had a message for the supermarket giants.

"Time's up. They need to step up and get rid of discounted milk."

Treloar said it had been quite an emotional time, and that came through in the video.

"It's a pretty tough time. We love our cows, we love what we do, that's why we do it. When that gets ripped away from you, yeah, it's going to break your heart."

But she said people were starting to get it.

"Something struck a chord, people are starting to listen.

"People are reaching out and saying they had no idea this was what we were dealing with, that this had become breaking point.

"While we may not be able to save our farm, hopefully the message gets out, that change can come about and save farms in the future."