الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 105 |  |  |
| | | from | 105 | | |
Abstract
Medicinal plants have been widely used in management of the infectious diseases and by now, many of the ancient remedies have proven their value through scientific methodologies. The success of herbal medicine in curing infectious diseases shows that many plants have beneficial effects in various bacterial, fungal, viral or parasitic infections.
Astragalus membranaceous is one of the important or adaptogenic herbs from the Chinese materia medica. It has been prescribed for centuries for its general debility and to increase the overall vitality of the immune system. Currently, many researches focused on its immune stimulating polysaccharides besides other active ingredients, which are useful in treating the immune deficiency conditions.
Despite the traditional use and the extensive studies of Astragalus membranaceous in nutrition as a growth parameter, its effects on the poultry immune response were not fully understood. Therefore, the current research was aimed for studying the immune-modulatory effect of Astragalus membranaceous herbal plant which can be achieved by analyzing a variety of chicken immune cells functions such as their phagocytic and bactericidal activities after feeding of chickens on the purified extract of Astragalus membranaceous. Moreover, quantitative real-time PCR assay was used as another useful tool for monitoring the immune status of chickens in response to Astragalus membranaceous administration via measuring the observed changes in cytokines genes expression levels in PBMCs.
Two hundred and ten, one day old SPF chicks were used for the experimental study. Chicks were acclimatized for 11 days before the onset of the experiment. The chicks were firstly divided into three major groups. The first group serving as a negative control. The second group received basal diet and Astragalus membranaceous extract and the third group received basal diet, Astragalus membranaceous extract and feed additives which are used as a commercial example of the farm diet. PBMCs of chickens under study were collected for studying the phagocytosis, killing assay with E. coli and cytokines` genes expression using the quantitative real-time PCR, whereas intestinal and spleen tissues were collected for the histopathological examination.