WASHINGTON - The House approved a ban on horse slaughter Friday after a confusing amendment about meat inspection caused two Republicans who initially had been sponsors of the ban to vote against it. Those sponsors, Reps. John Sweeney, R-N.Y., and Edward Whitfield, R-Ky., were among the lawmakers who voted against the spending bill that included the ban on horse slaughter. The spending measure passed 318-63. Sweeney and Whitfield say the amendment worked out behind closed doors made last-minute changes about meat inspection that were too vague to understand. “We had four different lawyers look at this language and we've come up with four different answers,” Whitfield said. Agriculture Department lawyers also said the provision was vague, he said. Sweeney said his “no” vote was a protest because the amendment in question was never debated in the open. The bill also must be approved by the Senate before it goes to the president for his signature. About 65,000 horses are slaughtered each year in the U.S. Texas and Illinois are the only two states that slaughter horses, which are processed for human consumption overseas. Sweeney and Whitfield said they will now push for a separate bill banning the slaughter of horses. The Cavel International Inc. plant in DeKalb survived a legislative attempt in 2004 to ban slaughtering horses for human consumption. The bill died in committee. Fire destroyed the DeKalb plant in 2002 but it was rebuilt and resumed operating in 2004. The fire did not appear to be intentionally set, Cavel officials said.