Before Britain entered the Common Market, almost the entire output of the Korumburra Butter Factory (South Gippsland, Victoria, Oz) was shipped to Britain. The only part of the production released locally was to the Royal Melbourne Show (where it regularly won the prize for Best Butter), the dairy farmer who supplied the milk to the factory and some local shops. It might not have competed with the Irish for freshness by the time it got to Britain but it was pretty good on the farm.
One reason it was so good was that all the cows were Jerseys, with 30% butterfat content. I do recall using the separator (and cleaning the thing afterwards, with its eleventy million bits) and winding the handle on the butter churn but I mostly remember the cows. In the early 50s we started getting Dutch immigrants, many of whom became sharefarmers on south Gippsland dairy farms. Not long afterwards we also started seeing gigantic black and white cows in the paddocks; Friesians!
There used to be a joke among Jersey-farmers, about the salesman who was pushing the use of Friesian semen in AI programs.
"Get some Friesians!" the salesman woud say. "Those Jerseys are useless. Put a two bob bit in the bottom of a 20 gallon milk bucket and you can milk a Friesian all day and barely cover the coin. Milk a Friesian and you'll fill the bucket at every milking!"
"Yair. And you can still see the two bob bit!" was the reply.