| Recombinant Immunocastration Vaccine of Boar
Boar taint sometimes arises when the meat of boars is heated, makes boar meat unsuitable for human consumption as meat. Surgical castration of young boars is a common practice to improve meat quality in current pig farming industry. But there are many problems in the aspect of severe pain owing to absence of anesthesia, vulnerability to pathogenic germs and decreased gaining weight after the operation. However, boar taint can be eliminated by immunological castration using a synthetic peptide vaccine against GnRH. NEXGEN has developed a chimeric peptide inducing immune response effectively against GnRH in animal. The chimeric peptide comprises modified multimeric peptide derived from GnRH as an immunogen and VP6 protein as a carrier, resulting in high immunogenicity. The efficacy of expressed protein in E. coli as an immuno castration vaccine was evaluated by measuring testis weight, body weight and the amounts of androstenone in back fat.
NEXGEN constructed chimeric gene comprising multimeric GnRH, VP6 from rotavirus and GST (VP6+GnRH+GST). To evaluate the efficacy of expressed and purified protein as an immunocastration vaccine, each 100 ㎍, 200 ㎍ or 400 ㎍ of proteins were injected via intramuscular (IM) route to 9 experimental groups of male rats. The immunization was started at 12 days age, 3 additional boostings were done in every 2 weeks after first immunization, and the rats were sacrificed 1 week after with the last injection for examination of genital organs. (Figure 1)
Figure 1. Inhibition Effect on testis and epididymis growth at 100 ㎍, 200 ㎍ and 400 ㎍ doses. 11 weeks after from the first immunization
Our improved vaccine is highly efficacious, cost-efficient and acceptable in market. It is providing a practically feasible alternative for surgical castration in pigs. The results described above indicate that the application of our new improved immunocastration vaccine would allow farmers to get profits with improved health conditions of pigs and better meat qualities. The Korean market size is estimated at US$5 million US and the international market size is around at US$48 million US annually. The great portion(60%) of the international market is East Asia which includes China.