Dairying probably originated in Neolithic times, when man first began to keep livestock. At first sheep and goats were the chief sources of milk but by the sixteenth century the cow had become the principal diary animal. At this period most cottagers had their own cow and processed its products for their own use. But by the mid eighteenth century many farmers were specialising in the production of milk, butter and cheese for sale. Victorian farmers who could afford to equipped their farms with modern dairies and the latest appliances; the less affluent made do with older and more homely equipment. Farm dairies were gradually superseded by large factory-based firms, but many of the objects used by many of the old farmers and country folk, such as milking stools and pails, churns for making butter, butter beaters, cheese vats, curd knives, and cheese presses, can be seen in museums, particularly in those devoted to rural life and old farming practice.