All U.S. beef imported into South Korea will come from cattle less than 30 months old, officials said Saturday, in a deal made to placate South Korean protesters worried about mad cow disease, according to AP. However, protesters were on the streets of Seoul again Saturday night, calling for a complete renegotiation of an April agreement to resume imports of American beef. Trade Minister Kim Jong-hoon announced Saturday on his return from talks in Washington that a screening system would be established to ensure that only beef from U.S. cattle less than 30 months old _ considered at less risk of mad cow disease _ will be imported into South Korea. Kim also said South Korea will have the right to inspect U.S. slaughterhouses, and will not import parts of cattle such as brains, eyes, skulls and spinal cords that can carry mad cow disease.