The present invention relates to a bovine VDJ cassette (BF1H1) that provides the novel ability to develop chimeric immunoglobulin molecule capable of incorporating both linear T cell epitope(s) (CDR1H and CDR2H) as well as conformational B cell epitope(s) (exceptionally long CDR3H). Further, multiple epitopes can be incorporated for development of multivalent vaccine by replacing at least a portion of an immunoglobulin molecule with the desired epitope such that functional ability of both epitope(s) and parent VDJ rearrangement is retained. The antigenized immunoglobulin incorporating both T and B epitopes of interest is especially useful for development of oral vaccines for use in humans apart from other species including cattle. The long CDR3H in BF1H1 VDJ rearrangement originates from long germline D-genes. The novel bovine germline D-genes provide unique molecular genetic marker for sustaining the D-gene pool in cattle essential for immunocompetence via selective breeding. D-gene specific DNA probe permits typing and selection of breeding cattle stock for maximum gemline D gene pool for better health and disease prevention. The bovine D-genes are unique to cattle and, therefore, provide sensitive and specific forensic analytical tool using molecular biology techniques to determine tissues suspected of bovine origin.