More than 7,000 birds have been seized during what is believed to be the largest cockfighting bust in US history, officials have said.
Ten people were arrested after police officers and other personnel surrounded the remote property in a canyon in northern Los Angeles County.
As well as the birds, firearms and drugs were found in the area.
Cockfighting, which is illegal in every state in the US, involves two birds fighting each other to the death.
Captain Jeff Parry, of the Los Angeles County Sheriff’s Department, told a press conference: “This, according to the experts here, is the largest seizure in US history of illegal cockfighting roosters.”
Most of those detained by his officers were “at the lower level, the caretakers, entrusted with feeding and caring for the animals”, while the property owner was the main suspect.
More arrests are expected, with some of those already detained caught after being chased through the canyon by mounted police officers.
Video of the raid shows officers discovering bodies of birds which Cpt Parry said bore “wounds consistent with cockfighting”.
As well as the birds, a number of mobile fighting pit and “hundreds of slashers” – which are attached to the animals feet during fights – were discovered on the site, along with syringes and steroids.
This is not the first time the property has been raided.
Eric Sakach, of the Humane Society of the United States, told the press conference that about 2,700 birds were seized in 2007.