CASH-STRAPPED dairy farmers are sending their prize cows to slaughter because they cannot afford to feed them as milk prices plummet.

The ABC's Four Corners program tonight reveals the devastating consequences of the country's major milk processor's decision to slash farm gate milk solids prices from $6 a kilo to well below $5 a kilo.

Next year that price will hit $4.31 a kilogram as Murray Goulburn continues to respond to what it describes as a weakening market.

Murray Goulburn  board members and senior executives are expected to tomorrow meet Prime Minister Malcolm Turnbull and Deputy PM Barnaby Joyce in Canberra to talk about the crisis.

Making the burden even worse for farmers is the fact that each season's payments are made in advance so  they have to pay back the difference between last year's price and this year's price.

It is estimated 2500 farmers owe about $200 million.

South west Victoria livestock agent Phil McVilly tells Four Corners that record number of dairy cows were sold to slaughterhouses within days of Murray Goulburn announcing its price cut in April.

The Charles Stewart Nash McVilly representative said about 700 dairy cows a week were heading to abattoirs in his region.

Farmer Kathleen Johnston and her family have no choice but to give up their southern NSW property because they stand to lose $70,000 a year if they keep dairying.

Ms Johnston said it broke her heart to send cows she had raised by hand to be slaughtered.

"Just the thought of selling your babies … you have pets, so that was hard," she tells Four Corners.

New Zealand's Fonterra has also cut its Aussie farm gate milk price.

Four Corners airs at at 8.30pm on ABC TV. - ARM NEWSDESK