Oetection of the Degree of Exposure to Newcastle Disease Virus In Ducks

Ot.lt of 827 exumined sera. of apparently healtl\Y’ ducks, 147·nnd 15 sa mplea showed HI and procipitating ant- ibodies to Newoc.stle disease virus (NDV). 2~ 5 Nemcc,stle diseuse virus isolates were recoveredfrom 348 cloncaJ. sevuls from appm-ently healthy dUcks.3 isolates were identified as velogenic strains of NDV. 4. Experimental infeotion of dUcklings passed fotal._5 • l~dul t du cks showe d asympt oml.e SB cour-se aft Ol:’ experi-