State law says that livestock headed for slaughter must be removed , euthanized . But federal law lets farmers determine if they can still , be fit for consumption . Justices express concern that state law may go too far into federal arena . The state counters that the two laws are compatible , allowing local conditions to be addressed and ensuring that moral and humane conditions are part of meat processing rules . Case was brought by a meat trade group on behalf of dairy farmers in California .
State law says that livestock headed for slaughter must be removed , euthanized . But federal law lets farmers determine if they can still , be fit for consumption . Justices express concern that state law may go too far into federal arena . Case was brought by a meat trade group on behalf of dairy farmers in California .