evaluating the effect of bacillus subtilis and licheni formis on performance of broiler breeder hens challenged with salmonella enteritidis

this study was conducted to investigate the effect of bacillus subtilis and licheni formis on broiler breeder performance and gastrointestinal health of their progenies. a total of 336 broiler breeder hens (cobb 500) from 22 to 32 weeks of age were used in a completely randomized design of 2 × 2 factorial arrangement with four treatments, each with seven replicates. dietary treatments included: 1) basal diet without probiotic and without salmonella enteritidis inclusion; 2) basal diet without probiotic and oral inclusion of 1×106 cfu/bird and 1×108 cfu/bird salmonella enteritidis in 26 and 30 weeks of ege, respectively; 3) basal diet containing 0.4 gr/kg probiotic and without salmonella enteritidis inclusion; 4) basal diet containing 0.4 gr/kg probiotic and oral inclusion of 1×106 cfu/bird and 1×108 cfu/bird  salmonella enteritidis in 26 and 30 weeks of ege, respectively. the results showed that adding probiotic was increased fractional weight of yolk and liver (p