* Brazil banned ractopamine on Nov. 12
* Drug was likely not used commercially yet in Brazil
* Government wants to set up segregated beef production
SAO PAULO, Dec 10 (Reuters) - Brazil said on Monday that it had temporarily banned a feed additive called ractopamine and other beta blockers that promote muscle growth in animals such as pigs and cattle because it fears being shut out of its largest beef importer, Russia.
The ban will be in effect until Brazil can set up a segregation system for beef and pork produced for foreign markets where ractopamine is banned in meat, said Carlos Mota, a representative from the Agriculture Ministry.
Ractopamine is in a class of drugs known as beta inhibitors or blockers that counteract the effects of adrenaline on the nervous system and slow the heart rate. In livestock, it promotes muscle gain.
Mota said the ministry had banned ractopamine and other so-called beta inhibitor drugs since Nov. 12, after Russia said it would require future meat imports to be free of the drug and that some exporting states would have to certify their meat.
Russia said on Monday that it would step up tests on U.S. and Canadian meat imports for traces of the banned feed additive.
The European Union and China already have certain restrictions on use of the drugs in meat.
"This is a question of time," said Alexandre Mendonca de Barros, director at local consultants MB Agro. "Brazil does not have any laboratories at this time set up to handle this type of testing and certification."
It is still not clear that Brazil had yet been using ractopamine on a commercial basis, said Jerry O'Callaghan, head of investor relations at JBS SA, the world's biggest beef exporter.
"In our understanding it was only used experimentally with quarantine restrictions this year. The impression from what the government is saying is that the product won't be used at any time until a reliable split system is in place that would be satisfactory to the countries that buy Brazilian meat," O'Callaghan said.
Brazil has exported 896,670 tonnes of beef between January and September and Russia imported 212,456 of it, according to data published by Brazil's meat exporters association Abiec.
Ractopamine is not authorized for human consumption but it is permitted as a limited feed additive for livestock by the United Nations.
For a FACTBOX on ractopamine click inside the brackets ) (Reporting by Reese Ewing and Peter Murphy in Brasilia)