title: Effects of dietary fat source and subtherapeutic levels of antibiotic on the bacterial community in the ileum of broiler chickens at various ages.
abstract: The effect of dietary fat source (soy oil or a mixture of lard and tallow) and dietary supplementation with antibiotics (a combination of avilamycin at 10 mg kg of feed(-1) and salinomycin at 40 mg kg of feed(-1)) on the bacterial community in the ileum of broiler chickens at different ages (7, 14, 21, and 35 days) was studied using PCR with denaturing gradient gel electrophoresis (DGGE) analysis and bacteriological culture. The bacterial origin of fragments in DGGE profiles was identified by sequencing. Bacterial enumeration results, together with PCR-DGGE profiles, showed that the composition of the microflora was age dependent and influenced by dietary fat source and antibiotic supplementation. An increased incidence of streptococci, enterobacteria, and Clostridium perfringens with age of the chickens was demonstrated. Lactobacilli and C. perfringens were the bacterial groups most strongly affected by the dietary treatments. Moreover, different strains (clonal variants of the alpha-toxin gene) of C. perfringens type A were detected in response to age, dietary fat source, and dietary supplementation with antibiotics.
authors.affiliation: Department of Animal Nutrition and Physiology, Danish Institute of Agricultural Sciences, Research Centre Foulum, Tjele, Denmark. Ane.Knarreborg@agrsci.dk
authors.forename: Ane
authors.initials: A
authors.lastname: Knarreborg
authors.forename: Mary Alice
authors.initials: MA
authors.lastname: Simon
authors.forename: Ricarda M
authors.initials: RM
authors.lastname: Engberg
authors.forename: Bent Borg
authors.initials: BB
authors.lastname: Jensen
authors.forename: Gerald W
authors.initials: GW
authors.lastname: Tannock
mesh_terms: D000367:Age Factors; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects / Q000302:isolation & purification*; D002645:Chickens / Q000382:microbiology*; D015169:Colony Count, Microbial; D004041:Dietary Fats / Q000008:administration & dosage*; D004591:Electrophoresis, Polyacrylamide Gel; D007082:Ileum / Q000382:microbiology*; D016133:Polymerase Chain Reaction
chemical_list: D000900:Anti-Bacterial Agents; D004041:Dietary Fats