But that milk from Hurlstone Agricultural High School's dairy farm could be a thing of the past if the State Government's plan to sell off the school's land is successful.

Fifteen cows from the school were transported to the Sydney Harbour Bridge for a milking display at the breakfast event, which was an initiative of the State Government.

In a press statement, NSW Minister for Tourism Jodi McKay said the Hurlstone cows added a special twist to the event.

``We have seen some remarkable things on the bridge including horses and F1 cars, now we can add cows to that list,'' she said.

But Tiffany Spiers, president of SHEAP, the campaign group trying to save Hurlstone, said the use by the State Government of the school cows was ironic given the same government is trying to get rid of the cows and the rest of the farmland at the school.

``I think urban Sydney needs to realise that it's not a matter of your milk coming out of your carton,'' she said.

``There are people out there struggling and trying to produce food to go on your table.

``If we lose land we will no longer have a dairy farm. Hurlstone should be a shop window into agriculture for Sydney.''

Ms Spiers said the school's contract with Dairy Farmers would be jeopardised if the land sale went ahead.

She said of the school's 115 hectares, 70per cent of that was used by the dairy farm. The school has 105 Ayreshire cows, 50 of which comprise the milking herd. ``Once you reduce our herd it becomes non-profitable,'' she said.

The independent inquiry into the proposed sale continues.