This is subjective. Each breed have certain characteristic. Depending on your needs, and the final product(s) you are looking for will help you decide which breed is best for you. Another issue is that depending on your location and whether or not the milk is for you family or a commercial operation will dictate the range of dairy or dual-purpose breeds you have to choose from. As far as milk quality Jersey cows are favored for their high butterfat, docile nature and are generally don't have problems when giving birth. Lately people have been breeding them larger and for greater milk production with less emphasis on butterfat. You also have Ayrshires which have moderate butterfat and are a hardy breed.
Milking Shorthorn's.
Dual purpose means that the breed or type of cattle can be used for milking or raising beef cattle.
Limousin cattle are a beef breed, not a dairy breed of cattle. So in other words, no not really. They have a milking ability that is matched to that of Angus, which is not nearly as good as Holstein or Jersey.
The most common breeds of dairy cattle are Holstein, Guernsey, Jersey, Ayrshire, and Brown Swiss. The Milking Shorthorn was originally used as a dual purpose breed, for milk and meat, but is now more often used for milk production.
Holstein-Freisians belong to the Dairy breed group of cattle. Beef Friesians, kin to the milking Holsteins, are in the beef breed group.
Charolais is the best beef breed, and Holstein is the best dairy breed.
No, Highland cattle are primarily beef cattle. They will not produce the amount of milk a dairy breed would, but can be milked.
a milking parlour
Not very well. Herefords tend to have low milking ability compared to other breeds like Holstein or even Angus. Herefords are a beef breed, not a dairy breed.
Milking the cows and cleaning the dairy parlour. Bringing the cows in from grazing for calving, milking, vet assessments/treatments. Mucking out.
By hand or with a milking machine.
Dairy farms can be laid out in almost any pattern as long as the barns or fields which hold the milking cows are connected to the milking parlor somehow.