"There was not quite enough demand to soak up the additional product offered," Kilsby noted.
At the latest GDT auction, anhydrous milk fat dropped 2.3 per cent to US$5,367 a tonne, while lactose fell 1.6 per cent to US$857 a tonne.
Meanwhile, rennet casein gained 3.3 per cent to US$6,473 a tonne, while butter milk powder increased 3.1 per cent to US$2,874 a tonne.
Cheddar rose 1.9 per cent to US$3,826 a tonne, while butter advanced 0.5 per cent to US$4,290 a tonne.
Skim milk powder held steady at US$2,621 a tonne.
The New Zealand dollar last traded at 69.21 US cents at about 12.17pm in New York, compared with 69.29 US cents at 5pm in Wellington the previous day.
There were 123 winning bidders out of 168 participating at the 13-round auction. The number of qualified bidders rose to 520, up from 516 at the previous auction.