Effects of Pueraria lobata leaf powder as a feed additive on the immune system and growth performance of broiler chickens

Abstract

The present research assessed the effect of different levels of Pueraria lobate leaf (PLL) on growth performance, immunity, antioxidant capacity, and blood index in broiler feed. A total of 384 at 21 days old chicks were assigned to 1 of 4 dietary treatments to examine the benefits of basal diet, basal diet +1% PLL, basal diet +2% PLL and basal diet +3% PLL. The trial was divided into 2 time periods, including starter from days 21- 49 and finisher from days 50-70. The addition of 2% and 3% PLL powder to diets increased total protein content, triglycerides, albumin, and low-density lipoprotein (p < 0.05). In contrast, total cholesterol, aspartate aminotransferase, urea nitrogen, and high-density lipoprotein in serum were reduced (p < 0.05). The levels of total antioxidants, superoxide dismutase, IgM, and IgG, on the other aspect, were significantly increased, nevertheless, the content of malondialdehyde and interleukin was decreased. Although dietary supplementation with PLL did not have an effect on the growth and slaughter performance, clear improvements in the thymus organ index, antioxidant performance, and immune functions (p < 0.05) were observed. The leaf of P. lobate is a strong candidate as a potential feed additive due to its wide range of sources and well-established record of safety, in addition to its efficacy in improving total protein, albumin, low-density lipoprotein, total antioxidant capacity, superoxide dismutase, Ig M and Ig G without any adverse effects on growth and slaughter performance. In conclusion, the leaf of P. lobate can be regarded as a novel resource for broiler feed additive to replace antibiotics.