Blame the cows: Kiwi dollar may stumble

Once billed as the hottest currency trade this year, New Zealand's dollar is set to stumble, tripped up by spilled milk.

"Since peaking in February this year, international dairy prices per Fonterra Global Dairy Trade (GDT) auction have fallen by almost 50 percent," Morgan Stanley (MS) said in a note Tuesday, noting that dairy products are New Zealand's largest export, accounting for 26.4 percent of the total.

"Due to New Zealand's specialization in whole milk powder (WMP) exports to China, we expect the fall in price and import demand to weigh on the New Zealand dollar (Exchange:NZD00H=)," the note said.

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It's a turnaround from the beginning of the year, when analysts had expected strong gains in the kiwi. BK Asset Management in January called the New Zealand dollar, also known as the kiwi, one of its favorite trades for the year, citing expectations the central bank would hike interest rates and increased demand for "soft commodities."

After starting the year around $0.8221, the kiwi climbed to highs of over $0.88 in July, but it has since stumbled, fetching around $0.79 in early Asia trade Wednesday.

Dairy prices face a lot of headwinds, likely keeping milk prices depressed for a while.

"We expect the recent peak in dairy prices, the lift of EU dairy quota and lower feed costs to increase global milk production," Morgan Stanley said, noting the USDA forecasts global dairy export volume to rise 10 percent in 2014.

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The EU dairy quota system, which fined countries for surplus production over a delivery quota, is set to be scrapped after the first quarter of next year, and Morgan Stanley noted that farmers there have already begun increasing their cow counts.

While New Zealand will likely continue to dominate WMP exports to China, media reports indicate the mainland's inventories are stocked up and lower prices aren't likely to spur additional demand, the note said.

Morgan Stanley forecasts the kiwi will fall to $0.76 by year-end and $0.67 by the end of next year.

Others are also citing lactophobia -- or fear of milk -- as a potential weight on the kiwi.

Fonterra has already noted that WMP prices needed to rise from the current $2,503 per kg of milk solids to $3,500 to meet its forecast payout, ANZ said in a note Tuesday, adding it doesn't expect the forecast will be met.

"Increases in dairy prices over November - should they occur - would not be a reason to buy the New Zealand dollar," it said.

ANZ also cited another concern: the country's low inflation rate, despite relatively strong economic growth.

"Lack of inflation leaves New Zealand dollar strength as the primary Reserve Bank of New Zealand (RBNZ) focus. They will maintain that the New Zealand dollar is overvalued, and they stand ready to act," ANZ said. "This should keep a cap on any New Zealand dollar strength over November."

In addition, ANZ cited concerns about increased market volatility globally.

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"Many market participants will be asking questions regarding exit plans from instruments that historically have been known to have 'small exit doors' (a feature synonymous with New Zealand dollar instruments)," it said. "This will reduce the attraction of the 'carry trade' as volatility adjusted carry has declined."

The central bank has set interest rates at 3.5 percent, offering a relatively attractive return compared with most developed markets' effectively zero interest rate policies.

ANZ expects the kiwi to fetch $0.78 by year end, falling toward $0.73 by the end of next year.

-By CNBC.Com's Leslie Shaffer; Follow her on Twitter @LeslieShaffer1