At least 62% of Indonesian chickens are resistant to bird flu due to a gene in their body called Mx, reports the Indonesian Institute of Science.

Sri Sulandari, a gene researcher at the institute's biological research center, said the indigenous chickens' ability to resist avian influenza varies according to the strength of the antivirus genes in their body. 

Sulandri added that since the birds may contain information on how resistant a specific breed is to the flu, culling them results in loss of crucial information.

Avian influenza was first detected in Indonesia in August 2003 and has now been found in birds from 31 of the archipelago's provinces. According to the Indonesia National Committee for Avian Influenza Control and Pandemic Influenza Preparedness, there have been 145 human cases of bird flu in Indonesia spread over 12 provinces. Of these, 119 have been fatal.