Besides banning the use of beta-agonist by pig farmers, it is also important to know whether the imported feed contains the banned growth enhancer, said Dr Chua.

Clean bill before slaughter
At present, 37 pig farms are placed under a one-month quarantine after their animals were found to have high levels of beta-agonist. This followed a check on 656 farms nationwide. Dr Chua said the farmers were allowed to send their pigs for slaughter after the quarantine period only upon receiving the green light from the Veterinary Services Department.
"Once the quarantine period is over, the farmers should inform the Veterinary Services Department which will then take samples from the pigs to ascertain whether they are free of beta agonist," he added. Only farmers who have made the declaration and received a clean bill from the Veterinary Services are allowed to send their pigs for slaughter.

So far only four farms whose quarantine period expired on Jan 14, have applied to the Veterinary Services Department to test their pigs.