Organic cranberry pomace and its ethanolic extractives as feed supplement in broiler: impacts on serum Ig titers, liver and bursal immunity

Citation

Das, Q., Tang, J., Yin, X., Ross, K., Warriner, K., Marcone, M.F., Diarra, M.S. (2021). Organic cranberry pomace and its ethanolic extractives as feed supplement in broiler: impacts on serum Ig titers, liver and bursal immunity, 100(2), 517-526. http://dx.doi.org/10.1016/j.psj.2020.09.044

Plain language summary

Due to the recent restriction of antibiotic use in broiler, cost-effective alternative products need to be developed to enhance the resistance to stress and diseases (immunity) in bird. Cranberry fruit pomace contains nutrients such as carbohydrates, lipids, proteins, and fibers as well as bioactive molecules including phenolic compounds known for their health benefits in human. Effects of feed supplementation with various organic cranberry products, to enhance the immunity of broiler chickens have been investigated. Analysis of blood collected from 21-day old birds showed that feeding with cranberry products influenced their blood defense proteins (called antibodies or immunoglobulins) levels. At 21-day of age, studies on liver and bursa indicated that cranberry products in feed reduced the level of pro-inflammatory markers in the liver while promoting the anti-inflammatory makers production in the bursa, suggesting beneficial effects on broiler immunity. Since there was no increase in stress related markers levels, the results suggest that birds were not exposed to any stress conditions due to feeding treatments or other management concerns. Overall results of this study showed that feed supplementation with cranberry products re-enforce immune responses in broilers in agreement with the hypothesis that berry products could be developed in broiler feeding as effective alternatives to antibiotics.

Abstract

With the pressure to reduce antibiotics use in poultry production, cost-effective alternative products need to be developed to enhance the bird's immunity. The present study evaluated the efficacy of cranberry fruit by-products to modulate immunity in broiler chickens. Broiler Cobb 500 chicks were fed a control basal diet, basal diet supplemented with bacitracin (BACI, 55 ppm), cranberry pomace at 1% and 2% (CP2), or cranberry pomace ethanolic extract at 150 and 300 ppm (COH300) for 30 d. Blood sera were analyzed at days 21 and 28 of age for Ig levels by ELISA. The innate and adaptive immune-related gene expression levels in the liver and bursa of Fabricius were investigated at 21 d of age by quantitative polymerase chain reaction arrays. At day 21, the highest IgY level was found in the blood serum of the CP2-fed birds. In the liver, 13 of the 22 differentially expressed genes were downregulated across all treatments compared with the control. Expression of genes belonging to innate immunity such as caspase 1 apoptosis–related cysteine peptidase, chemokine receptor 5, interferon gamma, myeloid differentiation primary response gene 88, and Toll-like receptor 3 were significantly downregulated mainly in BACI- and COH300-fed birds. In the bursa, 5 of 9 genes associated with the innate immunity were differentially expressed. The expression of anti-inflammatory IL-10 gene was upregulated in all treatment groups in bursa compared with the control. The expression of transferrin gene was significantly upregulated in livers of birds fed COH300 and in bursa of birds fed BACI, indicating feeding practices and organ-dependant modulation of this gene in broiler. Overall results of this study showed that cranberry product feed supplementation modulated the innate immune and suppressed proinflammatory cytokines in broilers, providing a platform for future investigations to develop berry products in poultry feeding.