Navid Jafari - Corresponding author: Jafari Navid. Department of Animal Science, Varamin-Pishva Branch, Islamic Azad University, Varamin, Iran

This study was conducted to evaluate the effect of a dietary mixed medicinal herbspowders (MHPs) (Thymus vulgaris, Pennyroyal, Cumin, Alhagi, Garlic and Eucalyptusglobules) on performance, egg quality and immunity response of laying hens. Theexperiment was carried out under completely randomized design, including fivetreatments (Treatment 1= basal diet without additive (control group), Treatment 2= basaldiet + probiotics at 0.1%, T3, T4 and T5=basal diet +1, 2 and 3% MHPs respectively)with five replicates (12 birds each replicate). 300 Bovans laying birds (49 wks old) weredistributed randomly in cages and allotted into one of experimental diets for 84 days. Theperformance was recorded every week. In order to examine the antibody against thesheep red blood cell (SRBC), 2 piece of hen from each replicate was randomly chosen(1cc) SRBC (%0.5) was injected and ten days later blood samples were collected. Toexamine the blood parameters (Serum Cholesterol, Red blood cells, White blood cells,Lymphocyte, Packed cell volume), In the day 70th , from each replicate 2 piece of henblood samples was taken. Egg quality parameters (High unit, specific gravity, shellweight and thickness and yolk cholesterol) at the end of the experiment were evaluated.Diets supplemented with 1, 2, or 3% MHPs had no significant effects on percentage ofegg production, egg weight mass, and feed conversion ratio (FCR). However, at the levelof 2 and 3%, daily feed intake decrease significantly (P< 0.05) compared to the control, probiotic and 1% MHPs. Probiotic and different levels of MHPs had no significant effecton SRBC. Probiotic and 1 and 2% MHPs significantly (P < 0.05) decrease IgG incompare to control and 3% MHPs. Using probiotic in the diet significantly increase IgMin laying hens in compare to control and different levels of MHPs. Probiotic and levels ofMHPs had no significant effect on egg weight, shell weight, shell thickness, specificgravity and haugh unit and serum cholesterol. However, MHPs at the level of 1%increase yolk cholesterol in compare to probitic, control, 2 and 3% MHPs significantly.In conclusion, using medical herbs in mixed form may suppress positive effect of medicalherbs in compare to using individually.

Medical herbs, Egg quality, Layer hens, Probiotic, Performance, Immunity