American Research Journal of Agriculture

Thecurrent study investigated the role of commercialprobiotic(ROEMIN W2)on growth performance and in preventing or treating chicks challenged with E.coli.Three hundred one day- old mixed Cobb broiler chicks, divided into 5 groups and reared for 42 days. G1was the control group. G2 received probiotic (ROEMIN W2). G3challenged with E.coli. G4challenged with E.coli after receiving of ROEMIN W2. G5challengedfirstly with E.coli then received ROEMIN W2. Body weight gain, feed consumption, and feed conversion ratio calculated for the complete experimental period. Two birds from each replicate were taken and slaughtered (at the 3rd and 6th weeks) for determination of carcass weight. Duodenum collected for both histomorphological and scanning electron microscope studies.ROEMIN W2 significantly improved performance in G2andG4 in spite of the E. coli infection compared to control group. G5 had the same FCR and carcass weight as the control group in spite of the E. coli infection. There was a significantly decreased growth performance in the E coli infected non ROEMIN W2 supplemented group, G3 compared to all other treatments. The collected data revealed pronounced intestinal villi improvement in groups treated with probiotic,while infected non- treated group showed decrease length of villi and increase depth of the crypts recorded. Scanning Electron microscope of groups treated with probiotics showed normal length long finger-like projection.Crypt area showed a numerous number of proliferating enterocytes having longer microvilli. Whereas the E. coli infected group showed short distorted duodenal villi with massive destruction and loss.