The embodiments disclosed herein relate to the design, engineering and production of replication-deficient gene delivery vectors that are based on aviadenoviruses. More particularly their use is described in the transfer of genes, genetic engineering of cells and animals, the expression of proteins the development of vaccines. In some embodiment, the designs and packaging of partially deleted aviadenovirus vectors are disclosed. In other embodiments, the designs and packaging of fully deleted aviadenovirus vectors, the propagation of replication-deficient aviadenovirus vectors, and the characteristic and engineering of host cells are disclosed. In other embodiments, the use of such vectors in veterinary medicine is described.