BATON ROUGE (AP) — Louisiana will ban cockfighting in August 2008, becoming the last state to outlaw the blood sport, under a bill granted final approval in the Legislature on Wednesday.

Gov. Kathleen Blanco is expected to sign the bill banning the rural tradition in which specially bred roosters fight to the death while spectators place wagers on the outcome. For years, state lawmakers resisted animal rights activists’ efforts to outlaw it, but relented this year on the condition that the prohibition take effect next year.

New Mexico, the only other state where cockfighting was legal, outlawed the fights earlier this month, increasing pressure on Louisiana lawmakers.

Sen. Art Lentini, the Legislature’s chief opponent of cockfighting, said he believed cockfighting’s popularity in Louisiana will actually end this summer, because lawmakers also approved an immediate ban on gambling at the rooster fights. Wagering is a major draw for the crowds that attend the fights at arenas throughout the state.

‘‘The gambling ban really puts an end to cockfighting. Betting is the real reason people go to those fights,’’ said Lentini, a Republican from suburban New Orleans.

Lentini and animal rights’ groups favored an immediate ban on the fights but bowed to strong opposition in the House, whose membership includes a handful of vocal cockfighting supporters.

‘‘We just didn’t have the votes in the House,’’ Lentini said.

Instead of Lentini’s immediate ban, the Senate voted 37-0 to approve a compromise measure by Rep. Harold Ritchie, D-Bogalusa, with the 2008 effective date. The measure would make it a crime to organize or enter birds in a cockfight. It would also close a loophole in Louisiana’s animal cruelty laws, which does not currently include chickens.

People in the cockfighting industry argued that an immediate ban would be unfair, leaving some of them with hundreds of chickens that are useless if the fights are illegal, because the animals are bred to fight. House members agreed that the cockfighters should have until next August to sell the birds or kill them off in fights.

Two senators skipped Wednesday’s vote, both of whom represent Cajun areas where cockfighting is widespread: Sens. Don Cravins, D-Opelousas, and Nick Gautreaux, D-Meaux.