South Korea has delayed a move to allow certain levels of the animal feed additive zilpaterol in beef to August from mid-July as it finalizes the policy, a food ministry official said. Seoul had already postponed the step to ease its zero-tolerance policy on zilpaterol-based drugs, such as Merck & Co Inc’s Zilmax, from June after a request by China. The official, who declined to be named, said South Korea would allow imports of beef muscle with 1 part per billion (ppb) of zilpaterol, 5 ppb in beef liver and 10 ppb in beef kidney as previously reported by Reuters. South Korea suspended some U.S. beef imports for more than two months last year after traces of zilpaterol were found in two shipments. Many other Asian and European countries also ban the additive due to concerns about its side effects. (Reuters)