Barbour, E.K., Sheib, H., Sagherian, V., Talhouk, R. and Talhouk, S. 2005. Immunopotentiation activities of Calendula officinalis and Centaurea aintensis against IBD (Gumboro) virus in chicken broilers
. Journal of the American Holistic Veterinary Association, 23(4): 15-20.
The objective of this study is to compare the impact of treatment by extracts of different herbs on index, presence of lesions, and heterophil count in the Bursa of Fabricius of broilers challenged with a high dose of an intermediate strain of Infectious Bursal Disease Virus (IBDV). Day-old broilers were divided into five groups of 11 birds each. Groups 1 and 2 did not receive any herbal extracts, while groups 3, 4, and 5 received daily known amounts of Calendula officinalis, or Centaurea ainetensis or a mixture of both extracts from 16 to 21 days of age. All groups, except for group 1, were challenged with live intermediate IBDV virus of 20 x log10EID50 per bird at 18 days of age. Group 1, deprived of extracts and challenge; group 3 receiving Calendula sp. extracts; and group 5 receiving a mixture of Calendula sp. and Centaurea sp. showed the highest Bursa of Fabricius indices (0.2755, 0.2382 and 0.2582, respectively, p<0.05), the lowest respective lesion scores (2 birds out of 11, 4 out of 11 and 4 out of 11, P<0.05), and the highest heterophil counts (4.41, 5.00 and 5.64 heterophils/2 fields/bursal tissue section, p<0.05). Groups 3, 4, and 5 which received herbal extracts, showed the lowest respective IBDV viral antigen counts in the Bursa of Fabricius (8.18, 9.1 and 8.27 /3 fields/bursal tissue section). C. officinalis water extracts helped birds in group 3 obtain the maximum clearance of IBDV from their Bursa of Fabricius.