Didn't see the earlier post about milking by hand and milk cans in time to reply. Reminded me of growing up on a small dairy farm in the early 60's and my dad had a milk route picking up cans and dropping off empties. I was about 6 years old at the time and still remember the farms and how many cans there were at each one. The largest farm had 18 cans. Smallest farm had 2 cans. We had about 6 cans. At that time there were 3 milk plants in the area and we dropped off cans at all of them. Once in a while one would come back rejected. If you opened the can the contents were a mess of straw, blood, etc. Finally the milk plants forced everyone to go bulk. Hard to find a milk can in good condition any more.