Dairy farmers are being urged to take steps to avoid a possible pasture shortage in spring.
Research organisation Dexcel says particularly cold and wet weather this winter has cut the amount of pasture feed available.
Cold, wet conditions inhibit grass growth and Dexcel said its monitoring of farms confirmed lower
than usual pasture cover nationwide.
The problem was pronounced in areas of the South Island and parts of the Manawatu, Wairarapa and East Coast in the North Island.
Dexcel farm systems specialist Chris Glasey said the cover was down about 200-300kg per hectare on normal. This meant pasture cover was at a lower level normally seen in September. Farmers would have to rely heavily on feed supplements in the next 6-8 weeks.
Glasey said farmers could also protect pasture from damage, rotate feeding areas in a way that allowed pasture to build up, use nitrogen fertiliser to stimulate growth and reduce feed demand by milking once a day or de-stocking.
He said many cows were not milking at present before calving - that reduced their feed demands.
One danger was that spring grass growth may not be as strong as desired, meaning less pasture available for cows getting back into normal milk production after calving.
"The big potential financial cost could come in September if we don't recover from this situation."
