Effects of verbascoside supplemented diets on growth performance, blood traits, meat quality, lipid oxidation and histological features in broiler chickens

A trial has been performed to evaluate the effects of dietary verbascoside (VB) on the growth performance, blood traits, meat quality and histological features of broiler chickens. Seventy-two male broiler chickens (Ross 708) were divided into three experimental groups (8 replicates): a control group (C, basal diet), a low verbascoside group (LVB, basal diet + 2.5 mg VB/kg feed) and a high verbascoside group (HVB, basal diet + 5.0 mg VB/kg feed). The animals were kept in cages, three birds per cage. The trial lasted 35 days. Growth performance and carcass yield were recorded. Blood samples were collected at day 35 in order to evaluate the blood, serum and plasma parameters. As a result of this study, growth and slaughter performances were not affected by the dietary treatments. The LVB and HVB groups showed significantly lower concentrations of total protein (P = 0.000), albumin (P = 0.000), α-globulin (P = 0.001) and β-globulin (P = 0.023) than the C group. The heterophil to lymphocyte ratio (H/L) was higher in the HVB group than in the LVB and C groups (P = 0.005). The thiobarbituric acid reactive substances (TBARS) results indicated lower lipid oxidation in the LVB group than in control. The most relevant histological feature was the lymphoid depletion observed in the thymus and bursa of Fabricius in LVB and HVB. Other studies are still needed to identify the optimal dosage and exposure time of VB dietary supplementation and to further investigate the effects of VB on lymphoid tissue as well as to establish the VB antioxidant effect on broiler chickens.