CHINA - A new study reveals that a ginger extract in the drinking water enhanced the response of chickens to oral vaccination against infectious bursal disease.
A ginger extract shows promise as an oral adjuvant for vaccination against infectious diseases in poultry, according to new research from China reported by L. Zhai and colleagues at Zhejiang University.
They explain in the journal, Poultry Science that infectious bursal disease (IBD; Gumboro disease), caused by infectious bursal disease virus (IBDV), is an immunosuppressive infectious disease of global economic importance in poultry.
Their experiment was designed to evaluate the effect of oral administration of ginseng stem-leaf saponins (GSLS) on humoral and gut mucosal immunity in chickens vaccinated with live IBDV vaccine, and furthermore, to test its protective efficacy against virulent IBDV challenge following vaccination.
In Experiment 1, chickens were orally administered with GSLS at 5mg per kg bodyweight for seven days, and then immunised with live IBDV vaccine via the oral route. Serum was sampled on 0, 1, 2, 3, 4, and 5 weeks post-vaccination for detecting antibody titres by ELISA, and intestinal tissues were collected at 0, 1, 3 and 5 weeks post-vaccination for measurement of IgA-positive cells and intestinal intraepithelial lymphocytes by immunohistochemical and hematoxylin-eosin staining, respectively.
Result showed that antibody titres, IgA-positive cells and intestinal intraepithelial lymphocytes were significantly higher in chickens drinking GSLS than the control, suggesting an enhanced effect of GSLS on humoral and gut mucosal immune responses.
In Experiment 2, chickens were delivered with GSLS and then vaccinated in the same way as in Experiment 1. The birds were challenged with virulent IBDV at three weeks post-vaccination. Then the birds were weighed, bled and necropsied on day 3 post-challenge and the bursae were sampled for gross and histopathological examination.
Results demonstrated that GSLS provided a better protection against virulent IBDV challenge following vaccination than the control.
Zhai and colleagues concluded that oral administration of GSLS enhances both humoral and gut mucosal immune responses to IBDV and offers a better protection against virulent IBDV challenge.
They added that, considering its immunomodulatory properties to IBDV vaccine, GSLS might be a promising oral adjuvant for vaccination against infectious diseases in poultry.
Zhai L., Y. Wang, J. Yu and S. Hu. 2014. Enhanced immune responses of chickens to oral vaccination against infectious bursal disease by ginseng stem-leaf saponins. Poultry Science. 93: 2473-2481. doi: 10.3382/ps.2014-04056
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