The 277-137 vote would restore a 1971 law preventing the Bureau of Land Management from selling the animals for commercial processing.
The protection was removed in 2004 when former Sen. Conrad Burns, R-Mont., inserted a measure in a spending bill allowing their sale.
"These animals were earmarked for death," said the bill's sponsor, Democratic Rep. Nick Rahall of West Virginia, chairman of the House Natural Resources Committee.
Supporters described the wild animals as American icons and said they are ending up on the plates of diners in France and Japan. The House voted last year and in 2005 to end the sales; the Senate never took up the issue.
"This is the latest overwhelming vote to stop the barbaric practice of horse slaughter, and it's now time for the entire Congress to finish the job," said Wayne Pacelle, president of the Humane Society of the United States.
About 29,000 wild horses and burros were on public lands as of February and the number should grow by a couple thousand with births of foals this year, said Lili Thomas, a national wild horse and burro specialist at the Bureau of Land Management.
Thomas said the agency wants the number at about 27,000 to 28,000. On average, the agency removes 10,000 wild horses and burros a year, but the number falls as the herd size gets closer to management levels.
About 5,500 animals are adopted each year and the agency spends about $23 million caring for those rounded up and not adopted or sold, she said.
The bureau halted sales of wild horses and burros in 2005 after 41 of the horses it sold were killed. Sales resumed under tougher restrictions against sales for slaughter.
Rep. Rob Bishop, R-Utah, said the bill eliminates a management tool for controlling the horse and burro population and preventing herds from destroying public lands by overgrazing.
He said the proposal does not prevent their slaughter for food because the animals are not supposed to be sold for that purpose by the government or used that way by the buyer.
Bishop could not resist injecting horse humor into the debate. "This bill is all hat and no saddle. I'm asking that the horse be with you and urge you to vote 'neigh' on this legislation," he said, interjecting a groan in his comments.
The bureau sells horses and burros that are older than 10 for commercial purposes for about $10 an animal if they have not been adopted at three auctions. The Congressional Budget Office said caring for the horses long-term would not cost more than an additional $500,000 a year.
The bill, H.R. 249, is the first of two horse slaughter measures Congress is expected to consider this year.
The Senate Commerce, Science and Transportation Committee approved a bill Wednesday that would outlaw horse slaughter nationally.
Animal protection groups have pushed for years to end the slaughter of horses whose meat often is sent abroad for people to eat, although some is used in U.S. zoos. But many horse groups and veterinarians oppose the bill.
Lawmakers stripped money for horse inspectors' salaries and expenses from the 2006 agriculture spending bill in an effort to end horse slaughter. But the Agriculture Department decided to offer horse slaughter plant inspections for a fee, keeping the three such facilities in the country in operation.
Instead, legal decisions have shuttered the plants. A federal appeals court has upheld a Texas law that prohibits horse slaughter to use their meat for food, closing two plants in the state.
A federal district court in Washington ordered the department to end the fee-for-service inspections, crippling operations at an Illinois horse slaughter plant.