Efficacy of Commercial Infectious Bronchitis Vaccines against Canadian Delmarva (DMV/1639) Infectious Bronchitis Virus Infection in Layers
Vaccination is the most important way to control infectious bronchitis (IB) in chickens.Since the end of 2015, the Delmarva here (DMV)/1639 strain of infectious bronchitis virus (IBV) has caused significant damage to the layer flocks in Eastern Canada.The efficacy of a combination of existing IB vaccines licensed in Canada was assessed against expe