Schoolchildren and visitors get a taste of how the white stuff is produced. And there’s not a thirsty cat in sight.

COSTA MESA ? Sitting in the shady corner of the Orange County Fairgrounds’ Millennium Barn on Tuesday, Rita Laughlin looks across the room and marvels at modern-day technology.

The Centennial Farm docent, who leads thousands of schoolchildren through a tour of the grounds every year, grew up on a farm in Oklahoma and started most days by waking up before sunrise to milk seven cows. As a child, before technology made milking both faster and cleaner, Laughlin did it the old way: by hand, with a bucket.

“It’s much better,” Laughlin said as the barn prepared to set up its first cow-milking of the afternoon. “A long time ago, they’d bring the cow in and milk it, and then the cow would step in the bucket, and there would be a cat nearby waiting for some milk. Finally, you would just give up and squirt some in its mouth.”

Back then, milking a single cow took as much as half an hour ? and dairy farms, as a result, had much smaller herds. Nowadays, the process takes less than 10 minutes and wears a lot less on the upper arms. As proof, the Centennial Farm offers public milking demonstrations every day of the Orange County Fair this summer.

During the shows, staff members from the farm ? which operates year-round on the fairgrounds ? set up two cows in a milking stall and hook up their udders to machines. The equipment, designed to simulate the feeling of a suckling calf, removes milk from the udders and splashes it into a clear glass tube below.

On Tuesday, staffer Roberta Harvey led a crowd of parents and children through the steps of a modern dairy, narrating the process as an assistant hosed the animals and connected the machines. Along the way, she threw out a few choice bits of trivia: for example, that the average cow weighs more than 1,000 pounds and is known as a “heifer” until it gives birth to a calf.

Luz Zamora attended the demonstration with her two children, and said it was an eye-opener for them.

“It’s very interesting for the kids, especially,” said Zamora, a Downey resident. “They don’t know where milk comes from.”

The Millennium Barn, located next to the Pacific Amphitheatre, features a number of farm-related exhibits. Inside is a chicken coop and a display for the charity group Heifer International, which provides livestock to Third World countries. Outdoors, the farm displays cows in stalls to give visitors a closer look.

For Laughlin, who taught middle school in Santa Ana for 37 years, working at Centennial Farm allows her to get back to her roots ? and also provides her with great stories, especially when children come through on tours.

“I give them a whole chicken to hold, and kids ask me if that’s one Chicken Nugget,” she said.