Bulk cream returns had nosedived as international demand had fallen, Wiseman reported, with further falls predicted in the coming months.
The company, which produces 80 million litres of bulk cream a year, said it was receiving 24ppl less for its cream than earlier this year.
"If cream prices show no signs of recovery in early 2009, we will have no option other than to address the ongoing shortfall this would cause through adjustment to our milk buying and/or selling prices," said chief executive Robert Wiseman.
Dairy Crest, which reported a a 7% drop in half-year pre-tax profit to £28.4m this week, said it was revising its profit forecast downwards as a result of the tough ingredients market and economic climate. "The board now expects adjusted profit before tax for the year to 31 March 2009 to be approximately 10% below last year," said chief executive Mark Allen.
The two companies' results come as Rabobank claimed in a new report that global demand for dairy would continue to be sluggish until at least the second half of 2009.
Dairy Crest's share price fell 25% on Monday following the announcement and the news that the company's earnings per share were down 77% to 4.7p.
"We are actively addressing these difficulties by continuing to invest in our business, particularly in the form of marketing spend and in the development of our operating facilities," Allen said.
Dairy Crest did at least report strong volume sales increases across its brands, with sales of Clover, Country Life, St Hubert and Cathedral City all up.
At its interim results last week, Wiseman reported turnover up 21% to £396m, but operating profit down 31% to £13.3m as a result of higher costs and delayed implementation of price rises. However its new £80m dairy would boost profits long term, it said.