Pathogenicity of clade 2.3.4.4 H5N6 highly pathogenic avian inflenza virus in three chicken breeds from South Korea in 2016/2017

In 2016, novel H5N6 highly pathogenic avian inflenza virus emerged in Korea. During the outbreak, the virus caused the largest culling, especially in brown chicken lines. We determined the pathogenicity and transmissibility of the virus in 2 white chicken lines of the specifi pathogen-free chickens, broilers and brown chicken line of Korean native chicken (KNC). A KNC had a longer virus shedding period and longer mean death time than others. Our study showed that this characteristic in the KNC might have contributed to a farm-tofarm transmission of the brown chicken farms.