Abstract
The effect of different levels of hogweed powder (HP; Heracleum persicum), flavophospholipol (antibiotic), and probiotics in diet on the performance, carcass quality, blood biochemical parameters, immunity, and intestinal flora of broiler chickens was investigated. In total, 270-day-old male broilers were randomly assigned to six treatment groups as follows: control basal-diet and diet supplemented with flavophospholipol, probiotics, or 0.25, 0.5, and 0.75% HP. Birds in each group were divided into three subgroups with 15 chicks each. Results indicated that the treatment groups did not vary with respect to feed intake (FI), whereas those supplemented with the antibiotic or 0.5% HP showed significantly higher body weight gain (BWG) and improved feed conversion ratio (FCR). Carcass characteristics did not vary among treatments, with the exception of abdominal fat percentage, which was the lowest in broilers fed 0.5% and 0.75% HP. Supplementation of 0.5% and 0.75% HP decreased plasma cholesterol and triglyceride levels. Furthermore, dietary HP significantly reduced serum low density lipoprotein (LDL) levels compared to that in the other groups. Antibody titers against Newcastle disease vaccine were not markedly affected by the treatments, whereas titers against avian influenza vaccine were significantly higher in probiotic- and 0.75% HP-supplemented groups. Antibody production against sheep red blood cells (SRBC) and IgM and IgG levels were not significantly different among groups. The ileum Lactobacillus counts in broilers fed 0.5% or 0.75% HP were significantly higher than those in the other treatment groups, whereas Escherichia coli counts in all treatments were significantly lower than that in the control. Therefore, our observations indicated that HP positively affected the gut microbiota and enhanced feed digestion. In conclusion, supplementation of 0.50-0.75% HP in broiler diet during the entire rearing period improved BWG and decreased abdominal fat deposition.