On February 15, 1882, the Dunedin finally set sail for Britain. She was loaded with 4,331 mutton, 598 lamb and 22 pig carcasses, 250 kegs of butter, hare, pheasant, turkey, chicken and 2,226 sheep tongues.
Source: How New Zealand lamb conquered Britain in the 19th century, by Andrew Forgrave, North Wales Live, 30 December 2015.
Within five years, 172 shipments of frozen meat were sent from New Zealand to Britain, mostly without mishap: it was a trade that grew to such an extent that, by 1957, New Zealand was exporting 14m lamb carcasses to Britain each year.
Source: ‘The road-makers eat meat three times a day’ by Grace Moore, Meanjin Quarterly, Autumn 2108.
The first successful shipment of antipodean frozen meat did not take place until 1879, when it sailed from Sydney, aboard the steamship the Strathleven, which docked in London 59 days later, with a perfectly preserved cargo. Mort, who also owned an abattoir, was keen to ship internationally, partly to offset his concerns relating to the falling price of wool (an anxiety for which Trollope would have had great sympathy) and partly because of a belief in making affordable, nutritious food available to as many people as possible, hoping to be able to sell it in England for six pence a pound (meat then cost between eight pence and a shilling per pound, depending upon the animal and the cut).
The UK imported meat from its colonies, hence ‘colonial meat’.
I’m not able to shine any light on the reference to ‘contract’.