Group 1 chickens were inoculated intraperitoneally with 10 LD50 of ORT/chicken/Shandong/2011 in 0.5 ml, and 100 ELD50 of H9N2/chicken/Shandong/2011 was administrated intranasallyin 0.2 ml at the same time.
Group 2 chickens were given 10 LD50 of ORT/chicken/Shandong/2011intraperitoneally in 0.5 ml and received 100 ELD50 of H9N2/chicken/Shandong/2011intranasallyin 0.2 ml three days later.
Group 3 birds were inoculated intranasally with 100 ELD50 of H9N2/chicken/Shandong/2011in 0.2 ml and three days later received intraperitoneally with 10 LD50 of ORT/chicken/Shandong/2011in 0.5 ml.
Group 4 birds were inoculated intraperitoneally with 10 LD50 of ORT/chicken/Shandong/2011in 0.5 ml.
Group 5 chickens were given 100 ELD50 of H9N2/chicken/Shandong/2011intranasally in 0.2 ml.
Group 6 birds received the sterile physiological saline intraperitoneally as a negative controlin 0.5 ml.