Active or passive immunisation against cholecystokinin-33 stimulates growth of pigs

The purpose of this study was to determine the effect of active or passive immunisation against cholecystokinin (CCK) peptide on feed intake and body weight gain in pigs. For active immunisation, recombinant CCK-33 concatenate polypeptide was employed to immunise pigs, while passive immunisation was achieved by egg powders containing CCK-specific antibodies from laying hens that were immunised with recombinant CCK-33 peptide. Enzyme-linked immunosorbent assay showed that the active immunised pigs had significantly higher levels of CCK antibodies in serum than the control ones (p<0.05). Actively or passively immunised pigs had significantly higher body weight, average daily gain and average daily feed intake than that of the control ones (p<0.05). The results suggest that active or passive immunisation against CCK-33 peptide has stimulatory effects on growth of pigs. Thus, immunisation against CCK-33 may be used as an alternative way to enhance pig growth.