This study was conducted to investigate whether dietary enzymes alter the caecal microbial profile of broilers fed sorghum-based diets. Four sorghum-based diets (918 g sorghum/kg diet) were prepared. One was the control diet and three had enzymes (xylanase, phytase andprotease) added. Broilers, 35-day-old, were reared (8 birds/cage) in an environmentally controlled shed and randomly allocated to replicated (n=4) assay diets and free access to feed and water all time. On day-42, birds were euthanized and caecal contents collected, pooled on a per/pen basis and frozen (-20 °C). The DNA was extracted from caecal samples using a bead-beating protocol and the V2V3 regionof the bacterial 16S rRNA gene amplified by PCR. Amplicons were separated on sequence difference using Denaturing Gradient Gel Electrophoresis (DGGE) and microbial profiles generated and compared.The DGGE profiles, when analysed, indicated that there was approximately 80% similarity between caecal microflora in all types of the diet treatments. This suggests that there was no overalldifference between any of the profiles and therefore the addition of different types of feed enzymes in a sorghum-based diet had no impact on the overall composition of the broiler caecal microflora.

Colibacillosis is animportant disease affecting the poultryindustry in many countries, caused bythe Avian Pathogenic E. coli (APEC):it manifests as various clinical signs. Itcontributes significantly to economicloss for poultry farmers as a result ofhigh mortality and morbidity in poultry.To overcome this, antibiotics have beenwidely used to eliminate E. coli infectionin poultry farms in recent years. Treatmentwith antibiotics has been considered as avital regimen to control E. coli infectionat the farm level for many years. However,high frequency of antibiotic resistance ofE. coli isolates from chicken has becomethe centre of attention due to public healthimportance. The aim of the present study isto determine the multidrug resistant profilesof E. coli strains isolated from chicken.E. coli isolates obtained from clinicalcases were re-identified and classified byconventional methods. Multidrug resistantprofiles against 13 different antibiotics of125 E. coli isolates were determined byusing disk diffusion method accordingto Clinical Laboratory Standard Institute(CLSI). Antibiogram revealed that 81.6%of the E. coli isolates showed multidrugresistant profiles to different antibiotics.Most of the E.coli isolates were highlyresistant to erythromycin (52.8%), followedwith tetracycline (52.0%), spectinomycin(39.2%), trimethoprim (38.4%) andflumequin (37.6%). Out of 125 isolatestested, 19.2% were resistant to more thaneight antibiotics, with one isolates found tobe multidrug resistant to most of antibioticsexcept polymyxin B. These findings alsodemonstrated that most of the isolateswere susceptible to antibiotics commonlyused for E.coli infections treatment inpoultry with lowest resistant score againstpolymyxin B (92.8%) and colistin (92.0%).Moderate resistant profiles were observedtowards amoxycilin (25.6%), apramycin(16%), kanamycin (8.8%) and streptomycin(8.0%). High percentage of multidrugresistance was found among the E. coliisolated from chicken as an indicator tomore serious problems in animal health.Therefore, continuous surveillance of antibiotic resistance profiles in chicken andother food animals is crucial to ensure foodchain safety