Establishment of an immunological labelling of pigs using synthetic peptides

The objective of this study was to develop a suitable combination consisting of synthetic peptides, carrier protein and adjuvant for immunological labelling of pigs. Specific antibody titres were evaluated by ELISA technique. From 9 peptides 4 were excluded from following investigations showing cross reactivity or low immunogenic effects, sufficient anti-peptide titres were achieved by 5 peptides. Labelling control is possible after 7 days at the earliest and can be used for the whole fattening period after single immunization using an effective carrier-adjuvant-combination. Mixing of peptides in one labelling dose had no negative influence on titres against single peptides. Different combinations of 4 carriers (keyhole limpet haemocyanin (KLH), palmitic-acid-3-cystein-acid (Pam3Cys), palmitic acid (Pam) and dextran) and 4 adjuvants (Montanide IMS 1313, Montanide ISA 25, Quil A and Diluvac forte) were tested. Optimal labelling could be seen by combination of 50 nmol peptide, KLH as carrier and Montanide IMS 1313 as adjuvant. Generally after booster injection titres were higher, however, a booster dose was not necessary using most effective adjuvants. A less immunogenic, but cost effective alternative for short time labelling (7 weeks) was a peptide-Pam3Cys-conjugate (75 nmol) combined with Quil A as an adjuvant (2 mg/ml). Immunological labelling of pigs is recommended as a good method for tracing back the origin of animals and meat products. It may be also used for vaccine labelling to prove vaccination of pigs.