Improved performance and immunological responses as a result of dietary Yucca schidigera extract supplementation in broilers.

This study aimed to study the growth performance and immunological effects of Yucca schidigera extract (YSE) in broilers. A total of 128 15-day-old broiler chickens were randomly assigned to four treatments: maize-soybean meal as the basal control diet or the basal diet containing either 100, 200 or 300 mg/kg of YSE. Each treatment was consisted of four replicate pens with eight broilers per pen. The experiment lasted 28 days. Body weight gain (BWG) and European broiler index (EBI) were recorded during grower period (d 15-28) and finisher period (d 29-42), respectively. On d 28 and 42, serum was collected to measure interleukin-1β (IL-1β), interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6), interferon gamma (IFN-γ), tumour necrosis factor alpha (TNF-α) concentrations and antibody titres against Newcastle disease virus (NDV) in broilers. During grower period, growth performance and serum cytokine concentrations were not exhibited differences except the decreased IL-6 concentrations. During finisher period, BWG and EBI were both increased at 100mg/kg group; IL-6 and IFN-γ concentrations were enhanced with 100mg/kg YSE incorporation, while 200 and 300 mg/kg YSE levels reduced IL-4 production. Antibody titres against NDV was improved at 100mg/kg YSE level in both grower and finisher period. We concluded that dietary YSE supplementation could improve growth performance and immunological functions in broilers. [ABSTRACT FROM AUTHOR]