The first apparent case of Mad Cow disease in the U.S. cattle population has been found in Washington state. Eight countries, including Mexico, Taiwan, and Japan have already banned US beef imports since hearing of the positive test. (UPI Photo/Mark Cowan)

Gov. Arnold Schwarzenegger Tuesday signed the measure that was introduced by Assemblyman Paul Krekorian after an incident involving downer cows that led to a massive voluntary beef recall in February.

Schwarzenegger called the measure a strengthening of California' overall food safety.

Krekorian told the Riverside Press Enterprise Wednesday the law could be used nationwide to remove any financial incentive that packers might have for slaughtering sick animals.

Federal law allows the slaughter of downer animals after they are checked out by a veterinarian and deemed "ambulatory."