Global Dairy Trade prices fell 0.9 per cent at the auction on Tuesday night.
Most prices were down by less than one per cent, although the butter milk powder price was down 7.5pc and the butter price 5.4pc.
Westpac NZ senior agr economist Nathan Penny said the result continued the sideways trend of the last few auctions.
"Accordingly, prices remain at very healthy levels," he said.
Whole milk powder prices, for example, were about 48pc higher than a year ago.
But Mr Penny said the auction result was a touch below the bank's expectations.
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Meanwhile, NZ production data for the 2020/21 season (April to April in NZ) is to be released soon and is expected to show a 2.5pc lift, a new record high, he said.
April production data was released last week and showed a whopping 11.6pc increase on last year.
"The result is even more impressive when you take into account that last season was also a record high level and that last season included an extra day (2020 was a leap year)," he said.
Mr Penny said the recent Canterbury floods posed a risk for the new season's production outlook.
"Notably, many farmers have lost winter feed during the floods, with feed stores already low given earlier dry conditions," he said.
"While this may not necessarily impact production levels from the spring, any additional adverse weather events certainly will.
"At this juncture, we expect a 2pc lift in nationwide production next season, with the very strong milk price likely to drive production higher, even with compliance and regulatory constraints acting in the opposite direction."
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