Characterization of the cecal microbiota of broilers fed with botanical extracts.

Introduction: The gastrointestinal microbiota of chickens is considered crucial for their welfare, growth and productive performance. Different bioactive plant compounds are being considered as potential alternatives to antibiotic growth promoters. Objective: To characterize the taxonomic structure of the cecal microbiota of broiler fed with the inclusion of botanical extracts. Methods: The experiment was carried out in Armero-Tolima with 704 one-day-old birds, distributed in 3 experimental groups, commercial diet (CP), diet including 200 ppm of grape seed extract (CNU) and diet with 200 ppm of green tea extract (CNT). At 21 days of age, 8 chickens per treatment were sacrificed. Cecum samples were taken from each individual and used for the extraction of microbial DNA. Sequencing of the 16S rRNA regions was done using the Illumina platform. The identification of the Operational Taxonomic Units (OTUs) was carried out using non-redundant databases as a reference from the 16S rRNA ribosomal marker. Taxonomic classification was performed by subsampling using MEGAN. Results and Discussion: The most representative bacterial phyla were Firmicutes and Bacteroidetes with approximate relative abundances of 84% and 3%, respectively. Other phyla such as Actinobacteria, Proteobacteria, Spirochaetes, Cyanobacteria, Tenericutes and Verrucomicrobia presented relative abundance around 1%. At the genus level, the most predominant OTUs in the cecal microbiota of chickens corresponded to Alistipes, Bacillus, Blautia, Clostridium, Eubacterium, Faecalibacterium, Lactobacillus and Ruminococcus, within which Lactobacillus and Clostridium presented a relative abundance of 16.8% and 11.5%, respectively. As observed in this study, it is known that Firmicutes, Bacteroidetes and Proteobacteria represent the majority (>90%) of cecal bacteria in chickens and that this bacterial community has important interactions between diet and the host. Conclusion: The main OTUs found in 21-day-old broiler chickens fed with botanical extracts correspond mainly to the phyla Firmicutes and Bacteroidetes and the genera Clostriduim and Lactilobacillus. [ABSTRACT FROM AUTHOR]