Skim milk powder fell 3.5 per cent to US$2358 a tonne. Skim milk powder "prices decreased across all contract dates, with the strongest decreases being for July contracts, down 5.0 per cent," according to Gibson.
"This reflects that buyers having adequate cover, particularly for short term contracts," Gibson added. "Furthermore, offer volumes leading into this event were up 54 per cent on the previous event, which is likely to have translated into a lift in volumes sold, adding further downward pressure on prices."
Anhydrous milk fat dipped 3.3 per cent to US$5530 a tonne, and lactose declined 2.2 per cent to US$875 a tonne.
Bucking the trend, rennet casein rose 2.3 per cent to US$7494 a tonne.
Butter milk powder was not offered at this event.
For sweet whey powder, no product was offered or sold, or no price was published for the last event, or on both of the two previous events.
The New Zealand dollar last traded at 65.26 US cents as of 3.28pm in New York, compared with 64.95 US cents at the previous close in Wellington.
There were 118 winning bidders out of 166 participating at the 13-round auction. The number of registered bidders was 527, up from 526 at the previous auction.