Dairy prices fell at Fonterra's global dairy auction on Wednesday night.
The global dairy trade weighted price index fell 3% to an average selling price of $US3545 per metric tonne.
Prices fell for almost all products, led by an 11% fall for anhydrous milk fat.
Whole and skim milk powder declined by 3% and 2.6% on average.
Rennet casein went against the trend, lifting by about 1%.
In December, Fonterra lifted its forecast payout to between $6.90 - $7 per kg of milk solids for the current season, citing a modest improvement in dairy product prices at auction.