At dusk, after all the fancy horses had been auctioned, Doug Barnes settled into a seat at the sale barn and got down to business. Three, four, five or more horses ambled into the ring at a time.

The auctioneer stopped making sales pitches. He looked straight ahead at the familiar visitor from Fort Collins, Colo., waiting for him to tip his hand. Barnes didn't disappoint.

In about 30 minutes, Barnes bought 25 so-called "killer horses." Their new owner would subject them to what animal rights groups say is a growing type of abuse: trucking them nearly 700 miles to Canada for slaughter, circumventing a U.S. ban on the practice. Much of the meat is eventually exported to countries in Europe and Asia for human consumption.

Stacy Segal, a horse specialist at the Humane Society of the United States, and other animal rights activists want a ban on exporting U.S. horses for slaughter abroad.

"They're jammed onto trailers with no regard for breed, size, age, temperament or sex and get no feed or rest," Segal said.

Last year, when state-imposed bans closed the last three U.S. horse slaughterhouses, a record 78,000 horses were exported to Canada and Mexico for slaughter, according to U.S. Department of Agriculture statistics compiled by the Humane Society. That's a 138 percent increase from 2006.

Statistics show that 76,100 horses have been slaughtered in Canada and Mexico so far this year. But the actual figure is likely higher because Canada hasn't yet reported two months' worth of slaughter numbers.

Barnes and others acknowledge that the long trip is stressful on the animals, but they blame animal rights activists who successfully pushed for all U.S. horse slaughterhouses to shut down. They say the increased exportation of horses is better than the alternative: horses being neglected and abused by owners who don't want them or can't afford to take care of them.

"In ranch country, people look at this as a necessary evil," Barnes said one late September day after buying five older horses for $135 apiece.

His boss, Charles Carter, is considered one of the largest buyers of killer horses in the country. Barnes, who scours sale barns in Nebraska, Colorado, South Dakota, Montana and Texas for Carter, estimates he has bought more than 1,000 horses for him this year alone.

Carter didn't return phone messages from The Associated Press seeking comment.

"We're doing them a favor by buying horses that might otherwise be neglected," Barnes said. "The big misconception animal rights people have is that all horses that go to slaughter are good, useable horses or pets ... when actually they're animals you can't do much with."

Slaughter opponents got a hopeful sign from Congress when a proposed export-for-slaughter ban was approved by the House Judiciary Committee in late September. But the bill got hung up in the Agriculture Committee during the final days of the session and will have to be reintroduced next year.

The long trip to slaughterhouses where the U.S. has no oversight isn't the only stress on horses destined for Canada and Mexico. They often spend days in feedlots, where they have blood drawn for tests necessary to get the health approval required for exportation.

Many of the horses are being bought at prices unheard of just a couple years ago. The U.S. slaughter ban, combined with overbreeding, a slack economy and high feed prices, have helped to create a glut of unwanted horses that has dampened the market. The last horse population census, in 2005, showed 9 million horses in the United States, up from about 5.5 million in the mid-1990s, Segal said.

Killer horses that used to sell for about 40 cents to 50 cents per pound before U.S. horse slaughterhouses closed now sell for about half that. At sale barns where Barnes used to compete with several other buyers, he's sometimes the only bidder.

Supporters of a ban on exporting horses for slaughter say the solution to the oversupply is to euthanize unwanted horses or take them to rescue organizations.

But capacity is a problem.

"Typically they're full," said Stephen Rei, president of the National Equine Rescue Coalition, which claims about 200 horse rescue groups as members.

That's the case at Valerie Hinderlider's horse rescue operation near Minden, Neb., Break Heart Ranch, which has 45 horses.

Hinderlider recently was forced to make a grim choice: She bought two horses so she could euthanize them rather than allow the previous owner to sell them for slaughter.

The price to kill and bury — anywhere from $100 to $250 — isn't one everyone can afford or is willing to pay. Nor is there room to bury all of the horses.

"What would you do with all these thousands of head of horses?" Rushville veterinarian Jeff Erquiaga asked, pointing to a trench outside the sale barn that has become a graveyard for euthanized horses.

Erquiaga said he's euthanizing about 25 percent more horses now than in the past. Still, the number he's put down so far this year — about 70 — is a small fraction of all the horses people want to get rid of.

Hinderlider suggested that horse owners seek out other buyers before turning to kill buyers. Many potential buyers have been scared away from sale barns because they've learned they can't compete with the likes of Barnes, she said.

"I've seen kids walk away crying because they got outbid by kill buyers," she said.

Michael O'Connell, of Mobridge, S.D., who has been buying killer horses for 40 years, isn't proud of his occupation but figures he fills a needed niche.

He said he buys thousands of horses annually, about half of them for a large Canadian supplier of horse meat.

"When I first started I hated it," he said while sitting in the sale barn. "I still don't like doing it. But if I didn't, somebody else would."