Effect of Milk thistle seeds on some egg characteristics, egg yolk lipids, serum metabolites, plasma minerals and serum liver enzymes activity in laying hens

To study the effects of different levels of Silybum marianum seed on some egg characteristics, blood metabolites, plasma minerals and serum liver enzymes activity in laying hens. The experiment was done on Hy-line strain (w36) from 32 to 42 weeks of age using a completely randomized design with 3 treatments, 4 replicates and 4 hens in each replicate. The experimental diets were: 1- control diet, 2- basal diet +1% powder of Silybum marianum seed and 3- basal diet +2% powder of Silybum marianum seed. The results showed that the average egg weight in treatment having 2% Silybum marianum significantly increased (P<0.05). Albumen percentage significantly was increased in treatment receiving 2% Silybum marianum (P<0.05). Shell strength, yolk percentage and haugh unit was not significantly affected by treatments, however haugh unit improved in treatments receiving Silybum marianum. Blood and egg yolk cholesterol and triglyceride concentration, also blood metabolites such as albumin, globulin, protein, glucose, urea, creatinine, HDL, LDL, calcium, phosphorous, magnesium and iron were not significantly affected by treatments. The activity of serum enzyme AST significantly was decreased using Silybum marianum (P<0.05). It is concluded that milk thistle or Silybum marianum has beneficial effects on egg quality and also decrease the level of liver enzymes activity in laying hens.