"Although TPP falls well-short of full liberalisation of dairy products, it will provide some limited new access for key traded products," Turner said.
"New Zealand exporters currently face prohibitively high tariff barriers on dairy products. Dairy exporters in NZ will benefit more from being within the TPP than if NZ remained outside it."
Turner said Japan, the United States, Mexico and Canada were four of Fonterra's top ten markets, and had a collective trade of US$2.56 billion in 2015.
At the end of the transition period, NZ will have limited quotas to export butter and milk powder to Japan, most cheese types and butter into the US, milk powder, cheese and butter into Mexico, and butter, cheese and milk powder into Canada.
Fonterra hasn't done any deeper analysis of the potential financial benefit from tariff removal, saying there was potential to draw inaccurate conclusions about the impact down the track and Turner dismissed the Government's projected gain from tariff reductions of up to $96 million at the end of the full term as "very hard to use as an indicator of full benefits".
"Tariffs are paid by importers, not exporters, so it does not necessarily change into a benefit for NZ," Turner said.
"The tariff savings are simply a crude proxy for trade opportunities which would result from greater market access. More market access will benefit our farmers, but trying to quantify that is very hard."
Zespri had a quantifiable number, $15m, which was their calculation of tariff removal in Japan, the kiwifruit marketer's most valuable market.
Zespri's chief operating officer Simon Limmer predicted a 33% growth in that market should TPP be ratified, although when asked how he could quantify the benefit to producers, he said the benefit would accrue more over time.
"It's not an immediate benefit back into growers' pockets, but the direct indirect benefit from that long-term investment and a sustainable position in that the long-term market is going to be very valuable," Limmer said.
"The $15m is the exact quantum in terms of what the tariff represents, but it will flow through in the market in terms of our ability to be more competitive.”
Six of Zespri's top 20 markets are present in the deal – Japan, Malaysia, the US, Singapore, Australia, and Canada – that had about $500m in collective sales in 2015.
Zespri is expecting a 50% increase from those markets to $750m in sales by 2020.
