Fig. 4
The survival rate of chickens subjected to aerosol exposure to NDV. Ten chickens per group were housed in an aerosol exposure cage with unidirectional airflow from a direct challenge cage. The cages were connected with hoses (70 cm long, 10 cm diameter, 1.5 m2/sec airflows). Chickens were monitored daily for 14 days to measure the clinical signs and mortality rate