Cal. Food & Agric. Code § 9164

In order to prevent the spread of any livestock disease, it is unlawful for any person, that does not have a written permit issued by the director, to remove, or cause to be removed, any livestock from slaughterhouse pens, yards, corrals, or similar holding places where livestock is held for the purpose of immediate slaughter, except directly into the slaughterhouse that controls such pens, yards, corrals, or similar holding places.