Hood,or other dairies,has not used rail for years. If my memory serves me,Hood's last attempt was to use "piggybacks"hauling their refrigerated truck trailers,sometime in the late 60's-early 70's on the B&M.
Hood was also a very EARLY user of trucks,and not just the old DIVCOs for route delivery. Being a "vintage heavy truck enthusiast",Hood was featured in a couple of Mack Truck advertisements from the 30's.
The Hood's milk plant in Portland,Maine has been in operation for years,and while adjacent to the former MEC mainline,just "east" of old Union Station,I don't remember it getting milk cars in(probably did when it was Portland Creamery-but before my time,which goes back to around 1950). This plant was/is for milk in the "Greater Portland Area."
As roads around here improved in the 1930's,farmers began shipping their "raw milk" in tank trucks. The early ones were "straight jobs",with a 1-2,000 gal tank. Independent contractors(or farmers disenchanted with running a herd of cows!) buying their own trucks,setting up a pick up route,and hauling the milk to Hood,or 2 other large dairies in Portland,neither of which were "on the railline". Mack's,Diamond T's,Whites,and Reos were very popular,and the hauls were fairly short,as there were many farms within 30 miles of Portland in the 50's.
Hood's also had an Ice Cream plant(built around 1950) about 3 miles east of the Portland Milk Plant. While it is also on the "mainline",at the west yard limit of Deering Jct. and MIGHT have got milk tanks in,I can only recall an L Model Mack tractor and 3,000 gal tank trailer,making short trips from the milk plant by old Union Station,in the 50's. A neighbor worked there,and we'd "visit" her at work,and she'd always give us a few "Hoodsies"!!
Bud