Tinkering with the Act would not answer some of the bigger questions facing the industry, he said.
The Government would now start a comprehensive review of the industry.
"By rolling over the Act and committing ourselves to a wide-ranging review we are taking a considered and strategic approach to the changing needs of the dairy industry," O'Connor said.
Terms of reference for the review, to be led by the Ministry for Primary Industries, would be published in the first half of the year.
O'Connor earlier told the Business Herald the review would look at pasture versus intensive farming, corporate versus family farming and environmental matters as well as competition and capacity.
Fonterra, owned by supplying dairy farmers and with listed units on the sharemarket, has been approached for comment.
Industry-good body DairyNZ said it was already working with the new Government and welcomed continued conversations and partnerships.
"These conversations started with the Dairy Tomorrow Strategy that looks to the future of the dairy sector and the role it can play in helping New Zealand," said chief executive Tim Mackle.