The effect of different forms and levels of silymarin on shell quality, carcass characteristics, some blood biochemical parameters, concentration of calcium, phosphorus bone and iNos gene expression in older laying hens

In this study, the effect of silymarin powder (SMP), nano-silymarin (NSM), and lecithinized silymarin (LSM) were considered on shell quality, carcass characteristics, some blood biochemical parameters, concentration of calcium, and phosphorus bone and iNOS gene expression in older laying hens. Materials and methods Seventy 80-weeks Lohmann LSL-Lite hens were allocated to 7 treatments with 10 replicates. Treatments included: 1) diet without silymarin (control), 2) daily intake of 100 mg SMP/kg body weight (BW), 3) daily intake of 200 mg SMP/kg BW, 4) daily intake of 100 mg NSM/kg BW, 5) daily intake of 200 mg NSM/kg BW, 6) daily intake of 100 mg LSM/kg BW, and 7) daily intake of 200 mg LSM/kg BW. The results indicated that all groups receiving silymarin showed an decrease in serum cholesterol content than the control (p <0.05) except those fed the SMP 100 diet. There were a decreases in iNOS gene expression in birds fed the NSM and LSM diets compared to control group (p < 0.05). Moreover, the effects of silymarin were more pronounced when converted to NSM or LSM and offered at the highest level (p <0.05). Overally, diet supplementation with 200 mg/kg BW of NSM or LSM to have been able to reduce blood lipids and iNOS gene expression.