Scottish pig farmers are taking part in a national demonstration in London over the refusal of supermarkets to increase the prices paid to farmers.
By Hayley Millar
BBC Scotland's business correspondent
Robin Traquair says he may end his pig farming days
Many claim that the latest rises in production costs are threatening to put them out of business.
Pig farmers have been struggling to cover their costs for the past decade, but the recent rises in cereal prices are forcing some farmers to reconsider their future.
In the East Lothian village of Millershill, the Traquair family have been breeding pigs for 40 years.
But the past 12 months have been the worst the family have known.
Robin Traquair has seen feed costs double in that time, forced up by global shortages of wheat and barley.
He said: "Barley has risen from £80 a tonne to £180 a tonne.
"Soya oil has also doubled from £450 to £860 a tonne and it's been the same for wheat."
At the same time, Robin has seen the price he is paid for his pigs rise only slightly.
"We've had 2p or 3p a kilo more, but we need around 28p or 30p a kilo to cover our costs," he said.
Over the years the farm has changed - outbuildings are being converted into offices to bring in money and a mobile phone mast now towers over the farmyard.
In the past, the rental income from the mast had been useful to help tide the farm over, but now it only provides three weeks' income.
After 25 years as a pig farmer, Robin said he was now seriously considering getting out.
"The pigs have been subsidised by other parts of the business that we've diversified into, but we can't keep subsidising it.
"And we're not going to subsidise the people who eat bacon, nor the people who want to buy it in the supermarkets."
Are you affected by the issues covered in this story? Are you a farmer? Do you work in the animal feed industry? Send your comments and experiences using the form below:
The BBC may edit your comments and not all emails will be published. Your comments may be published on any BBC media worldwide.