1a. Objectives (from AD-416):
Conduct research that will lead to the development of scientifically sound and commercially applicable phytonutrient-based strategy to mitigate the negative effects of necrotic enteritis. Study basic immune mechanisms that are associated with enhanced innate immunity.
1b. Approach (from AD-416):
Immunological and genomics tools will be applied to 1) Identify innate immunity pathways which are affected by dietary phytonutrients, 2) Identify molecular pathways associated with NE resistance in genetically divergent lines of broilers, and 3) Analyze gut microbial composition after phytonutrient treatment.
3. Progress Report:
With increasing regulation on the use of antibiotics in poultry production, there is a new thrust to find alternative drug-free strategies for growth promoting and disease control for farm animals. In order to best utilize the available information on the dietary modulation of immunity for developing 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, the effects of dietary supplementation with an organic extract of turmeric (Curcuma longa) on systemic and local immune responses to intestinal infection with the parasite Eimeria maxima or Eimeria tenella was evaluated in commercial broiler chickens. Infected chickens given the turmeric extract-containing diet had increased body weight gains, reduced parasite survival, and decreased gut lesions compared with infected birds given a non-supplemented control diet. The turmeric extract-supplemented diet also was associated with increased systemic antibody response, as assessed by greater levels of serum antibodies to an Eimeria-specific protein, and an increased immune cell response. At the gene level, the expression of a significant number of genes in a specific type of immune cell (lymphocytes) present in the gut was altered in birds fed the turmeric extract. Based on the known functions of the corresponding mammalian genes, the intestinal gene products altered with the addition of tumeric extract in the diet was consistent with an anti-inflammatory response in the gut. Taken together, these results suggest that dietary tumeric may attenuate inflammation-mediated gut damage induced by Eimeria parasites, and thus represents a possible alternative to current drug- and/or vaccine-based strategies to control Eimeria infections (Coccidiosis) in commercial poultry production.