Effect Of Herbal Additives Of Milk Thistle (Silybum marianum) And Nettle (Urtica dioica) On Immune System Parameters, Blood Metabolites And Egg Yolk Cholesterol In Laying Hens

The present study was carried out in order to investigate the effect of different levels of herbal additives of milk thistle and nettle on performance indices, immune parameters and egg yolk cholesterol. A total of 90 laying hens were randomly assigned to 5 treatment groups, 6 replicates of 3 birds each in a completely randomized design. Dietary treatments included control group and different amounts of milk thistle (0.5 and 1.5%) and nettle (0.5 and 1.5%). Results showed that adding of milk thistle (1.5%) to laying hens ration improved egg mass and feed conversion ratio (P<0.05). Using of milk thistle and nettle had not effect on shell quality. The highest yolk index was found out in the eggs from hens that were fed 1.5% of milk thistle in contrast to hens fed the control treatment without milk thistle (P<0.05). Egg yolk cholesterol amount was not affected by different levels of milk thistle and nettle powder. There were no significant differences in concentrations of glucose, triglyceride, cholesterol and HDL in plasma. Using of milk thistle (1.5%) fortified immune indices by decrease of heterophile percentage and heterophile to lymphocyte ratio (P<0.05). Therefore, it can be concluded that the supplementation of laying hens diet with milk thistle (1.5%) has positive effects on performance and immune system.