____________________________________________________________________________________________ *Corresponding author: Email: torki@razi.ac.ir; Annual Review & Research in Biology 3(4): 921-934, 2013 SCIENCEDOMAIN international www.sciencedomain.org Effects of Commercial Prebiotic and Probiotics of Diet on Performance of Laying Hens, Egg Traits and Some Blood Parameters Ahmad Mohebbifar 1 , Seifollah Kashani 1 , Meysam Afsari 1 and Mehran Torki 1* 1 Department of Animal Science, Agriculture Faculty, Razi University, Imam Avenue, Kermanshah, Iran. Authors’ contributions This work was carried out in collaboration between all authors. All authors read and approved the final manuscript. Received 6 th April 2013 Accepted 2 nd August 2013 Published 9 th August 2013 ABSTRACT Aims: This study was conducted to evaluate the influence of adding commercial probiotics and prebiotic to diet on performance of laying hens, egg traits and some blood parameters. Study Design: Data of feed intake (FI), egg production (EP), egg mass (EM), and calculated feed conversion ratio (FCR) were analyzed based on completely randomized design using GLM procedure of SAS. Place and Duration of Study: All procedures used in this 7-week experiment were approved by the "Animal Ethics Committee of Razi University" and complied with the "Guidelines for the Care and Use of Animals in Research". Methodology: Five iso-caloric and iso-nitrogenous diets (ME =2720 Kcal/Kg and CP=150 g/kg) including basal diet (control) and basal diet supplemented by probiotics (PrimaLac®, A-Max and Yeasture) and prebiotic (Fermacto) were formulated. A total number of 90 Lohmann LSL-Lite laying hens were randomly divided in 15 cages (n=6). The experimental hens were 56-wk old with an average egg production rate of 90.6 ±4.8% and 1,460±24 g live body weight. Hens in every 3 cages (replicates) were assigned to feed on one of the 5 experimental diets. Results: FI, FCR, EM, EP, egg weight, egg traits (egg index, yolk index, Haugh unit, yolk color, shell weight and thickness) and blood parameters were not affected by adding Research Article