| The present experiment was conducted at poultry farm - Agriculture College –University of Baghdad for the period of 27th May 2005 to first of Jully 2006. The aim of this study was to determine the effect of dietary supplementation with probiotic , prebiotic and synbiotic on productive characterstics and mortility of White Leghorn (WL) laying hens . A locally prepared probiotic were used each one gram of this probiotic contain at least 1010 Colony Forming Units of Bifidobacterium , L.acidophilus bacteria and 108(CFU)of Saccharomyces cerevisiae yeast and Aspergillus niger fungal , respectivally . The Prebiotic used in this study consist of a non starch oligosaccharide of S.cerevisiae yeast after crashing of cell wall .The synbiotic used in this study were prepared by mixed equael amount from probiotic (Iraqi probiotic) and prebiotic . Atotal of 180 WL laying hens , 16 weeks old were randomly allocated into four treatment groups. Hens in T1 group were fed a standerd laying diet and used as control group . Hen in T2,T3 and T4 were fed diet supplement with 5 Kg/ton of probiotic , prebiotic and synbiotic , respectively . Egg production were measured monthly throughout of the experimental period .The data of the present study showed that feed supplementation with probiotic , prebiotic and synbiotic were significantly (P<0.01)decreased abnormal egg about 23.0% , 18.1% for (T3,T4) , mortality about 40.4%, 47.2% ,87.6% for (T2,T3,T4) , and improved egg weight about 3.0% ,0.8% , 1.0% for (T2,T3,T4) and percentage of settable hatching egg about 1.93% , 1.61% for (T3,T4) . It could be concluded from this study that proiotic , preiotic and synbiotic did have a benifial improvement in egg weight and percentage of settable hatching eggs for the hens that were fed these feed additives for 12 months production period . |