Grass was in such short supply that the entire herd was being allocated a total area of only 2ha a day for grazing.
Along with many other farmers throughout Wairarapa, the farm was relying on feeding out precious supplementary feed such as silage, and was feeding imported palm kernel.
Earlier, during a morning tea session at Wild Oats cafe, Carterton, Mr Shearer quizzed Wairarapa Federated Farmers members about the impact of the big dry in the district.
President Jamie Falloon said "water storage is the key".
Not only would captured water solve irrigation woes, it would also protect rivers from low summer flows.
Mr Falloon said while dairy farmers were facing decisions such as relying totally on feeding out and of drying off herds early, sheep farmers had culled their ewes, sold off surplus lambs and were contemplating whether they would have to sell off capital stock.
He said by urging the Government to declare an official drought, farmers were "not simply looking for hand-outs".
"Water storage that would give us a guaranteed supply has got to be the answer," Mr Falloon said.
Mr Shearer said his visit to Wairarapa was to "get a first-hand account of what is happening and to learn from farmers what relief they will need". He said Labour "like everyone else" wants to get a good line on the situation "and to help the best way we can".
IrrigationNZ - a national body representing irrigators - has joined the push for water storage projects.
Chief executive Andrew Curtis said storage needed to be "fast tracked" to drought-proof agriculture. He said the summer drought had already cost the country more than a billion dollars.
"The answer lies with a combination of regional and on-farm water storage development," Mr Curtis said.