Cecropin AD (CAD), a hybrid antimicrobial peptide composed of the first 11 residues of cecropin A and last 26 residues of cecropin D, is a promising antibiotic candidate. Therefore, an efficient and convenient method for producing CAD is necessary for commercial applications. The Newcastle disease virus (NDV) has been widely used as a platform for gene delivery and exogenous protein expression. In this study, we constructed a recombinant NDV that expresses CAD. To obtain high expression of the CAD peptide, tandem repeats of the cad gene were inserted into the genomes of the thermostable NDV strain TS09-C using reverse genetic technology. The thermostable recombinant NDV, namely rTS-CAD