1a. Objectives (from AD-416):
To evaluate intestinal gene expression associated with dietary immunomodulation using phytonutrients.
1b. Approach (from AD-416):
Broiler chickens will be treated with various phytonutrients and their effects on avian immune response to mucosal pathogens will be evaluated using established disease parameters and various immunological assays.
3. Progress Report:
With increasing regulations on the use of antibiotics in poultry production, there is a new thrust to find alternative drug-free strategies to promote growth and control disease in farm animals. In order to best utilize the available information on the dietary modulation of immunity to develop alternative disease control strategies in poultry, detailed studies on immune mechanisms mediated by various phytonutrients, that is health promoting plant-derived nutrients, were carried out. In this reporting period, we evaluated the effect of anethole, a chemical obtained from anise or fennel oil, on in vitro and in vivo immune response parameters in chicken. In vitro studies showed that anethole reduced the viability of the invasive infective stage of the parasite Eimeria acervulina after 2 or 4 hours of treatment by 45% and 42%, respectively. It stimulated a 6.0-fold increase in the growth and cell division of chicken spleen cell compared with controls. Broiler chickens continuously fed from hatch with an anethole-supplemented diet and challenged with live Eimeria acervulina eggs had an increase in body weight gain, a decrease in parasite survival, and higher serum antibody titers to the parasite compared with infected chickens given an unsupplemented diet. Dietary feeding of a day-old chickens with an anethole-supplemented diet activated chicken genes that control inflammation. Taken together, these results suggest that dietary anethole may attenuate inflammation-mediated gut damage induced by Eimeria parasites. Thus, it suggests a possible alternative to current drug- and/or vaccine-based strategies to reduce gut damage caused by the Eimeria-derived intestinal disease Coccidiosis in birds.