Lawmakers are again trying to stop horses from being slaughtered and sent abroad for food.

The House adopted a provision Thursday that would prohibit the Bureau of Land Management from selling wild horses and burros to slaughterhouses. By voice vote, the amendment was attached to a spending bill for the Department of the Interior, the BLM's parent agency.

American horse meat is sold mostly for consumption in Europe and Asia, though some goes to U.S. zoos.

"Horses are icons in American culture," said Wayne Pacelle, president and CEO of the Humane Society of the United States. "They took us into battle, provided us with transportation and even carried our mail."

"They shouldn't be sent to slaughter to be dismembered for overseas consumers," Pacelle said.

Defenders of the practice said slaughter is more humane than allowing wild horses to die of starvation.

"When you talk about a horse dying a natural death on the range, it's not a pretty picture," said former Rep. Charlie Stenholm, D-Texas, now a consultant to the slaughter plants. "Having a coyote or wolf eating a dying horse is not a pretty picture."

There are more than 32,000 free-roaming horses and burros on public lands — about 4,000 more horses than those lands can support, according to the Bureau of Land Management.

"The people who voted for that amendment, they are not thinking about what happens to the horses if they don't go to slaughter," Stenholm said.

Congress has tried to address the issue in the past. Lawmakers eliminated money in this year's federal budget for the salaries and expenses of horse meat inspectors in the Agriculture Department. In response, three slaughter plants, two in Texas and one in Illinois, worked with the Agriculture Department to establish a fee system financed by the companies.

The Humane Society filed a lawsuit in federal court, saying that Congress had intended to ban horse slaughtering. But a federal judge ruled in March that the slaughtering can continue.

Pacelle argued that horses can be skittish, making them prone to thrash about when they are frightened.

"They see other horses that are being slaughtered and they are terrified," Pacelle said.

Stenholm said horses are treated better than other animals, such as cattle and chickens, at slaughter plants.

"We do a pretty darn good job regarding the welfare of the animals that are going to be slaughtered," Stenholm said.

Horse meat is a small business compared with the beef, pork and poultry industries. Plants slaughtered about 88,000 horses, mules and other equines last year, according to the USDA.