Global dairy prices dipped slightly at the Global Dairy Trade Auction on Tuesday night.
The GDT price index was down 0.4 per cent.
But the overall result disguised mixed results for different categories.
The key Whole Milk Powder index rose 2.6 per cent and the Butter Milk Powder index rose 10.8 per cent, but other indexes were all down.
The biggest fall was in the skim milk powder index - down 4.5 per cent.
The 0.4 per cent dip meant prices have fallen at consecutive auctions after six consecutive rises.
Prices fell 0.8 per cent at the previous auction two weeks ago.
Butter prices slipped 0.1 per cent but over the past year they have doubled.
New Zealand ASB economist Nathan Penny put the high levels down to a change in sentiment.
"Much of this surge in milk fat prices can be put down to an acknowledgement by the scientific community that fats are no longer as bad for your health as once feared," he wrote in the ASB's latest Farmshed Economics.
"In particular, this notion has been embraced in North America. In short, butter is back!"
While the global dairy market outlook remained firm, Mr Penny expected prices to fluctuate around current levels over coming months.
"So far, this calm bodes well for our 2017-18 milk price forecast (for NZ) of $NZ6.75 a kilogram milk solids."
Production rates in Europe declined 1.6 per cent during the first four months of 2017. New Zealand output is expected to increase during the next 12 months.
AgriHQ said prices for nearer-dated WMP contracts lifted more than prices for later dated ones, suggesting some buyers needed WMP more urgently than others.
Large stocks of SMP still available from Europe were responsible for bringing prices of that product down.
Buyers from North Asia and from the Middle East bought more product than they did at the June 20 event.
A total of 28,574 metric tonnes of product was sold. There were 165 participating bidders, with an average price of US$3303 per tonne.
with New Zealand Farmer