Dairy and aluminium exports have buoyed a 1% rise in the monthly ANZ commodity price index, which has also benefited from prices boosted by global trade tensions.

The forestry sector also managed its 20th consecutive month of growth, albeit only gaining slightly.

Of the 17 indexed commodities seven rose, five were unchanged and four declined, ANZ Agri economist Con Williams said.

"The main thrust was provided by the dairy complex, while aluminium provided a supporting act as trade tensions and geopolitics boosted prices," he said in a statement.


However, the meat and fibre group of commodities provided a drag, as beef and skin prices fell.

The New Zealand dollar lost ground against the US dollar and the British pound, but moved higher against most major trading partners, helping boost New Zealand dollar returns 1.2% month on month and lifting annual growth to 5.8%. Mr Williams said dairy prices had continued to push higher in April, up 2.7% month on month and 7% on a year ago.

He said the gains were due to a range of influences, including what appeared to be sluggish European production across some of the larger export regions of Germany, France, the UK and Netherlands during their seasonal peak, which also happened a year ago.

The other major influence appeared to be broad-based demand creating inter-market competition, Mr Williams said.

Aluminium prices jumped 8% because of trade and geopolitical tensions, especially because of US trade sanctions on Russia.

"China's clampdown on excess production and capacity restrictions to improve air quality continue to support prices."

Forestry prices "ground higher" by 0.2%, marking 20 months of consecutive gains, and domestic and export log and lumber prices were still well above last year because of solid demand both domestically and from China, he said.

"However, upward momentum has flattened out recently."


Beef prices fell 4.2% on increased manufacturing beef supplies from New Zealand, Australia and the US, while venison and sheepmeat prices remained stable at high levels.

Wool prices continued to lift off earlier lows, up 2.6% monthly and 11.7% on a year ago.

Wool prices were driven by bargain hunting, demand boosted by current price competitiveness versus substitutes.