effect of milk thistle (silybum marianum l.) on biochemical parameters and immunity of broiler chicks fed aflatoxin b1 after three weeks

background: this study was conducted to determine the efficacy of milk thistle seeds (mtss) in counteracting the toxic effects of aflatoxin b1 (afb1) in a contaminated diet fed to broilers.methods: two dietary inclusion rates of afb1 (0, 0.250 and 500 ppb) and mts (0, 0.5 and 1%) were tested in a 3×3 factorial manner. the effect of nine experimental treatments was assessed using 216 one-d-old ross 308 male broiler chicks in a randomized complete design with 4 replicates of 6 birds each from one to 21 days of age. the effects of dietary afb1 and mts on serum biochemistry factors, antibody titer against newcastle disease (nd) and influenza disease (id) in broilers were evaluated at the end of this period. results: statistical analysis of the main effects of diets indicated no significant changes in uric acid, cholesterol, triglycerides, low density lipoprotein (ldl), id, and phosphorus compared to the control (p>0.01). also, addition of 500 ppb of dietary afb1 into the diet was associated with significant decreases in serum glucose, calcium, high density lipoprotein (hdl), and nd compared to the control group (p<0.01). the contaminated diet significantly increased the activities of aspartate aminotransferase (ast) and alanine aminotransferase (alt) (p<0.05). conclusion: milk thistle showed protective effects and resulted in some serum enzyme activities and serum biochemical changes associated with aflatoxin toxicity.