A vaccine composition for castrating pigs, comprising a peptide immunogen and a veterinarily acceptable delivery vehicle or adjuvant, wherein the peptide immunogen comprises (a) a LHRH peptide of SEQ ID NO: 1, and (b) at least one T helper epitope selected from a group consisting of SEQ ID NOs: 2, 3, 4, and 5, and, optionally, an immunostimulatory peptide of SEQ IN NO: 6, wherein the LHRH peptide is covalently linked through its N-terminus residue to the T helper epitope or immunostimulatory peptide. A method for castrating or inhibiting characteristics, including boar taint, induced by the sexual maturation of pigs using the vaccine composition is also disclosed.
