The livestock tent is on the far end of a sloping macadam midway at the Prince George's County Fair. So Monday night's rain flowed down the asphalt and settled in great pools in the animal pens.

"It cooled them down," said Kent C. Mayne Sr., looking at the hogs he had hauled from his upper Montgomery County farm.

But to Bill Howard, selling lemonade across from the Wacky Shack where mirrors make the long-and-lean look squat, what brought the pigs pleasure kept the customers away.

"I've never seen it so bad," he said.

Rural and urban meet, but rarely mingle at Bowie Race Course this week at the Prince George's County Fair, an event that is still organized as an old-fashioned county fair complete with blue-ribbon competitions for sheep, hogs, goats, steers, chickens and geese. But Prince George's is 95 percent urban these days, and without Kent Mayne and other out-of-town farmers the livestock tent would be almost deserted.

"We stuck our heads in to the animals," said Pat Southerland, who came to the fair from Laurel with her two daughters and a nephew. "But we like the rides better."

It was different 20 years ago, when the fair was held in Upper Marlboro and herds of livestock were on parade. "You'd get U.S. Senators here with huge herds then," said Don Westcott, fair manager.

But 20 years and a Capital Beltway later, the county's population has doubled as the percentage living in rural areas has fallen by half. The acres of land in tobacco have dropped from about 8,000 to 4,000, and only one dairy farm remains in the county.

The Prince George's fair once reflected these changes. In fact, there was no livestock at the fair when Westcott took over in 1975. He built up the livestock exhibits year after year, believing that even city folk would be interested in them. But exhibitors and visitors have been difficult to attract, as Prince George's has left the farm behind.

"We don't seem to have got the spreading effect," said David Conrad, an agricultural agent who spent four hours on Wednesday night in the livestock show-ring with the Maryland Lamb Wool Queen, Carol Irvine, from Gaithersburg. Many of the prizewinning steers, sheep and goats also were from other Maryland counties. And many of the people watching were exhibitors.

Farms still thrive in Prince George's east of the Beltway and south of Rte. 50, but most county residents live in the north and west.

"I've never had any animals," said Shelby Norris, as she strolled through the carnival area. Norris said she grew up on a farm, but now lives in Forestville.

And Oxon Hill resident Tim Bliss, who came with his wife Lauren and his son Troy, said: "I threw a little money away on the games, but we're not really interested in the livestock. We're city slickers, I guess."

Fair organizers knew they had to do something to attract city slickers like Bliss. "How many people do you have that have cows and pigs, and grow tobacco?" Westcott asked. So 4-H members, on whom Westcott depends for farm exhibits, opened new competitions: model rockets, electrical projects and school-lunch competitons, for instance. Entries inceased.

But corn, soy beans and tobacco -- staples of Prince George's farmlands -- are sparse at the fair. Some bundles of tobacco, the fast-burning 609 variety that European importers seek to keep their cigarettes burning evenly, were spread out on tables. But every leaf on show came from a single farm, Merton Canter's 25 acres in Mitchellville.

There was more activity in the green and white livestock tent, where more than 600 chickens were on show, although few of them were Prince George's natives. Even the poultry section supervisor, a portly actor named Dick Holmes, who played Linda Blair's doctor in Airport '75, was from Montgomery.

"The problem is that Prince George's is so suburbanized," Holmes said.

Debora York, 14, of Upper Malboro and Linda Ralph, 18, of Forestville stayed clear of the hogs and chickens, the corn and soybeans. In their frilly dresses, they waited for their next performance in the Guys and Gals square dance group. Debora and Linda like country music, but said they know little about the country.

"I live in the Holly Hill Apartments right in the center of Forestville," said Linda. None of the 54 country dancers in Guys and Gals lives in the country, she said. The only livestock they own are cats and dogs, she said.

So country is waning at the Prince George's County fair. But Westcott said that's exactly what makes this fair all the more important: City people can see a world they left behind.

"It's one of the most important parts of a fair," he said.

But Harold Stevens, a retired agricultural scientist and the master of the Beltsville Grange, one of the oldest farmers' organizations in the country, sat all Wednesday evening with his display on agricultural history, and it attracted almost nobody.

The Beltsville Grange has 65 members, he said, none of whom are farmers, although Stevens has a garden in his back yard. "We lost our last farmer when the Beltway was built," he said.

But some kids still want to farm.

"I wouldn't like to go on the rides," said Jon Hagerty, a 13-year-old Montgomery boy who raises sheep and had them on show at the fair. He guarded them all night, sleeping in a hammock slung over the pen.

"I want to buy a farm, get a couple of Angus, some sheep, some hogs," Jon said. "I like hogs better than sheep."