Plant Extracts, Energy, and Immune Modulation in Broilers

Abstract

This chapter presents information obtained from experiments involving male Ross 308 broiler chickens on the effects of a standardised combination of plant extracts (PE) including carvacrol, cinnamaldehyde and capsicum oleoresin, on bird performance, hepatic antioxidant concentration and immunomodulation. Birds were reared under industryrecognised environments and were fed one of four diets. There were two control diets based on either wheat or maize, formulated to be iso-energetic and iso-nitrogenic. The other two diets were the control diets supplemented with 100 g per tonne of PE, respectively. Feeding PE improved dietary feed efficiency, dietary net energy and hepatic antioxidant contents of the birds, but did not change dietary metabolisable energy (ME). Overall, feeding PE reduced the mRNA transcript levels of three cytokines (IL-12B, IFN-G, and IL-6) and the marker CD 40 LG in caecal tonsils. Dietary PE may maximise the nutritional value of feed through improving gut health by reducing intestinal inflammation. Their mode of action is associated with improved dietary energy availability, immune status and hepatic antioxidant contents of the birds. However, studies that have focused solely on the effect of PE on ME alone may not have detected their full benefit to improve the efficiency of broiler meat production.

Potential of a mixture of eugenol and garlic tincture to improve performance and intestinal health in broilers under necrotic enteritis challenge

“…Further, a recent study suggests the beneficial effects of a microencapsulated product composed of eugenol and garlic tincture on BWG and FCR under a subclinical NE ( Pirgozliev et al, 2019 ). In contrast, reviews compiled with several studies did not observe beneficial effects of PE on performance parameters and intestinal health ( Demir et al., 2003 ; Windisch et al., 2008 ; Wallace et al., 2010 ; Pirgozliev et al., 2018 ). The inconsistent findings observed in field studies could be attributed to the variations in the origin, type, composition, form, inclusion level, health status, and the heterogeneity of experimental conditions, thus warrants further research.…”

Review of herbal medicine works in the avian species

“…In poultry, plant extracts containing a mixture of cinnamaldehyde, carvacrol, and capsicum oleoresin as immunomodulators, showed regression of CD 40 LG, interferon (IFN)-G, and interleukin (IL)-6, indicating low inflammation, especially in the digestive tracts against avian coccidiosis caused by intestinal protozoan parasites and Eimeria spp. [ 95 ]. The overall effects were confirmed by higher levels of serum antibodies and enhanced pro-inflammatory cytokine production in the duodenum.…”