Post time is heralded by a loud trumpet. The crowd pushes against the rails, yelling for their favorites. The field -- Bacon Bit, Pork, Beans and Magnum P.I.G. -- is loaded into the gate. Nervously, the contestants await the signal. Then the bells sound and the pigs burst down the track in a mad dash.

It's Centreville, another stop in the busy schedule of the Robinsons' Racing Pigs, a Tampa, Fla., group that has been performing at county fairs, shopping center openings and other special events since 1984.

"My husband and I first started pig racing as a one-time thing for the Florida State Fair," said owner and promoter Carlota Robinson. "It was so popular, we stuck with it. Now we have six units of eight pigs traveling the country 11 months out of the year. We appear at literally thousands of events and have been to every state."

Two of Robinson's units have made the trip for the night's event: the grand opening of the Centrewood Shopping Plaza. The 16 hogs present include Hammy Davis Jr., Marvelous Marvin Hogler, Hock Hogan and Oinkle Sam.

Trainers Al Pringle and the husband and wife team of Randy and Linda Ross of Yee-Haw Junction, Fla., coordinate the races, introduce the pigs and explain what makes the animals tick. They're with the animals 24 hours a day, keeping the hogs company and on a balanced diet.

"We teach them by using a repetition and reward system," said Randy Ross. "Pigs have a big sweet tooth. When we begin training them, we dot the track with cookies and after a while, the pigs catch on. If they don't win, they are not going to get their cookie. The losers just get crumbs."

"They do catch on fast, though," Pringle said. "They are just as smart as dogs and they can make a great house pet. Pigs have gotten a bad rap all these years for being dirty. The thing is, they don't have a sweat gland. They wallow in the dirt and mud to keep cool. But pigs are not unclean. We even house-train them."

The pigs race only for Oreo cookies, not Chips Ahoys or Pepperidge Farm Distinctives. Just Oreos. "We've tried Hydrox and generic Oreos, but they only like the real thing," Pringle said.

As in any sport, the question of what makes a champion stand out from the ordinary pig has to be asked.

"Just the desire to race," Pringle said. "Pigs are just like people. They have different personalities. Some are real enthusiastic and ham it up for the crowd. Some of these pigs will never win a race no matter how hard they try."

Of course, there are legends in the pig racing game. Orsen, now studding on the Robinsons' farm in Pennsylvania, is held the fastest pig ever. He ran the 150-foot oval track in four seconds. Among present racing heavyweights are Cookie Monster and Big Bertha. They will have to enjoy their fleeting fame. A pig usually races in the weight range of 20 to 120 pounds, then goes on to farrow (give birth to a litter of pigs) or is donated to the 4-H and other youth farming programs.

Meanwhile, back at the race track, Bacon Bit is in the lead by a length with the pack closing in. But she slides out of control on the straightaway. Pork, and then Beans, speed by her. Smelling victory, Pork turns on the steam. In a photo finish, she wins by a snout. Pork basks in her victory, chomping the well-earned prize, an Oreo cookie.

Another race is about to begin. While Linda Ross snatches people out of the audience to cheerlead for each pig, Al and Randy escort the pigs from their trailer to the gate. Nearly everyone will cheer by section for their assigned pig. "Please," says Randy Ross, "move away from the rail. It's awfully embarrassing to have a pig jump into your lap."

Youngsters Latisha Woodson and Joe Woodson of Centreville are amused by the pigs.

"I saw them in the first race," Latisha said. "I was really surprised. I thought they were slow."

Spectator Helen Groff of Centreville takes so many photographs, it would make the people from Kodak beam. Not only does she follow every race, she goes to the trailer between events to pet the pigs and get some close-ups. "I love pigs. They are my favorite thing in the whole world. I'm going to get these pictures and plaster them all over my room at home and at my office. The people I work with thought I was crazy when I told them I was going to the pig races."

Vicki Chapman of Manassas, carrying a stuffed pig, volunteers to wear a pig nose and stand next to the gates to cheer on the races.

"Ever since I read 'Charlotte's Web,' I've loved pigs," Vicki said. "I collect all sorts of pigs in crystal and ceramic. I have them all over my house. I can identify with these guys. I can understand running for Oreos. I love them, too."

When the race ends, the Rosses begin loading the pigs back in their trailer. "Sometimes people don't understand what we do," Randy said. "We'll be at a gas station and somebody will come up and say that they also raise pigs. Then I'll say, 'No, I don't raise them, I race them.' " They always walk away muttering something about a straitjacket."