Abstract
Moringa oleifera (MO) is a widely used as the nutritious and non-traditional feed supplementation containing kinds of bioactive substances. However, the enhancement effect of Moringa oleifera leaf Polysaccharide (MOLP) as a feed additive in broilers growth performance and immunity remains unclear. In this study, MOLP was obtained by water extraction and alcohol precipitation method, then purified with Trichloroacetic acid (TCA) assay. Chickens were randomly divided into 4 groups, to receive different doses of MOLP (0, 0.1, 0.2, 0.4g/kg) in feed for 3 weeks. The body weight gain (BWG) and feed consumption were recorded for feed conversion ratio (FCR) and average daily feed intake (ADFI) calculation. Broiler chickens were sacrificed and sampled on day 14, 21, 28 (D 14, D 21, and D 28) respectively. Serological indicators, including total protein (TP), albumin (ALB), globulin (GLO), and creatinine (CREA) were detected. ELISA kits were applied for detecting the levels of immunoglobulin A (IgA), immunoglobulin G (IgG), interleukin-2 (IL-2), and tumor necrosis factor (TNF-α). From D 21 to D 28, the results showed that middle dose of MOLP significantly increased BWG and ADFI as well as liver and bursa indexes when compared with the control group. In addition, TP and GLO were also increased (P<0.05). All MOLP treatments enhanced the serum concentrations of IgG and IL-2 (P<0.01). Furthermore, results of quantitative RT-PCR showed that high dose of MOLP treatment significantly increased (P<0.001) the mRNA expression levels of IL-2 and TNF-α of chickens relative to the control group. In conclusion, the results showed that MOLP supplementation contributed to improve growth performance and immune response in broiler chickens, and MOLP could be considered as a promising feed additive.