At the latest GDT auction, lactose sank 9.7 per cent to US$744 a tonne, while skim milk powder fell 3.9 per cent to US$2,209 a tonne.
Rennet casein declined 3.7 per cent to US$6,574 a tonne, while cheddar weakened 2.3 per cent to US$3,430 a tonne, and anhydrous milk fat decreased 1 per cent to US$4,954 a tonne.
Butter slipped 0.3 per cent to US$3,891 a tonne.
Bucking the trend, butter milk powder jumped 9.3 per cent to US$2,408 a tonne.
The New Zealand dollar last traded at 72.14 US cents at about 12.50pm in New York, compared with 72.75 US cents at 5pm in Wellington the previous day.
There were 125 winning bidders out of 166 participating at the 13-round auction. The number of qualified bidders rose to 617, up from 616 at the previous auction.