A nucleic acid sequence encoding a fragment of the adenovirus fiber capsid protein, a DNA construct including a replicable expression vector and at least one heterologous nucleic acid, and recombinant protein including fragment of the adenovirus fiber capsid protein. The fragment comprises the C-terminal knob and part of the shaft domain of the fiber protein of these adenoviruses. The use of recombinant proteins as an active ingredient in vaccinating compositions for conferring to an animal immunity against a pathogenic infection by an adenovirus, and methods for vaccinating a domestic bird against a pathogenic adenoviral infection.