Abstract: An in vivo replicative and recombined porcine adenovirus characterized in that it comprises a heterologous nucleotide sequence inserted into the porcine adenovirus in conditions enabling the latter to be replicated in vivo and to express the inserted heterologous nucleotide sequence, and in that the adenovirus genome comes from a 3 or 5 serotype (PAV-3 or PAV-5) adenovirus. Insertion occurs in a non-essential zone of the E3 region, preferably with deletion of said zone. The invention also relates to a recombined porcine vaccine comprising one such porcine adenovirus. The invention further relates to a serotype 3 or 5 porcine adenovirus vector that is replicative in vivo and is deleted in a non-essential region of the genome thereof. The invention also relates to a DNA fragment comprising all or part of the referenced SEQ ID NO.5 nucleotide sequence.