Wellesbourne man Richard Band has milked 2.5 million cows - that's 70 million pints - over more than 40 years at Warwickshire College.
Staff at the Moreton Morrell centre have praised the herdsman, who retired just before Christmas.
At an end-of-term presentation, centre manager Mike Bailey said Mr Band had started work at 5.30am and milked 100 cows, twice a day, 12 out of every
14 days, for more than 40 years.
He added: "At today's yields and prices, this equates to about 40 million litres or 70 million pints that Richard has sent to the bulk tank.
"The value of the milk Richard has produced is about £10 million at today's farm gate prices.
"I think you would all agree that there are very few people that will ever make that sort of contribution to college or for that matter to the national economy, in a working lifetime."
He described Mr Band as a man of few words, but a "thinking man's herdsman", always thinking about ways to improve the farm - including inventing his own backing gate for the milking parlour.
A keen gardener, Mr Band has also won prizes at the Wellesbourne and Walton Flower Shows, and for his allotment.
Pictured: College principal Ioan Morgan (centre) with Mr Band and his wife Judith. ns
