Anyone ever been to Fair Oaks Farm over in NW Indiana?
They milk around 36,000 cows three times per day, produce over 250,000 gallons of milk per day, birth 80-100 calves per day, and use digesters to convert the manure into methane that not only powers all of their electricity needs, it powers their AG equipment, and their fleet of semi's that deliver all of that milk. They also sell electricity back to the grid. They own around 30 square miles.
They send all the heifer calves to KY and TN to graze (better grazing ground) until they're ready to be bred. Then they artificially inseminate them. A month or so before they are ready to give birth, they bring them back to Indiana. They give birth and head off to the milking barn for the rest of their life.
Each barn has about 6000 cows. They are all RFID tagged. The cows decide if they want to be milked and walk themselves to the milking parlor. If they arrive too early, a gate sends them to the back of the line. If it's been long enough, it lets them through. They step on to a slowly turning 72 stall turntable, someone closes a gate behind them, disinfects their teats, and hooks up the milker. Every cow is monitored for milk production.
There's more. It's really fascinating. If you ever get the chance to go, do it.
The last time we were there, we were on a bus with a load of Wisconsin dairy farmers. The overwhelming comment was "I'm glad I retired when I did."