Bacterial Succession in the Broiler Gastrointestinal Tract

Abstract

bA feeding trial was performed with broilers receiving a diet of wheat-based feed (WBF), maize-based feed (MBF), or maize-based concentrates supplemented with 15% or 30% crimped kernel maize silage (CKMS-15 or CKMS-30, respectively). The aim of the study was to investigate the bacterial community compositions of the crop, gizzard, ileum, and cecum contents in relation to the feeding strategy and age (8, 15, 22, 25, 29, or 36 days). Among the four dietary treatments, bacterial diversity was analyzed for MBF and CKMS-30 by 454 pyrosequencing of the 16S rRNA gene. Since the diets had no significant influence on bacterial diversity, data were pooled for downstream analysis. With increasing age, a clear succession of bacterial communities and increased bacterial diversity were observed. Lactobacillaceae (belonging mainly to the genus Lactobacillus) represented most of the Firmicutes at all ages and in all segments of the gut except the cecum. The development of a "mature" microbiota in broilers occurred during the period from days 15 to 22. Striking increases in the relative abundances of Lactobacillus salivarius (17 to 36%) and clostridia (11 to 18%), and a concomitant decrease in the relative abundance of Lactobacillus reuteri, were found in the ileum after day 15. The concentration of deconjugated bile salts increased in association with the increased populations of L. salivarius and clostridia. Both L. salivarius and clostridia deconjugate bile acids, and increases in the abundances of these bacteria might be associated with growth reduction and gastrointestinal (GI) disorders occurring in the critical period of broiler life between days 20 and 30.

Gut Microbial succession during conventionalization of germfree chicken

“…A similar finding was observed in the ceca of broiler chickens where Clostridiaceae-related sequences formed 65% of the 16S rRNA clones derived from various age groups (14). Also, other studies that analyzed the effect of age on cecal microbial composition found that Firmicutes predominated and composed more than 90% in one-week-old chicken and decreased with age to 56% by 35 d (6,7,35). Among the Firmicutes, Ruminococcaceae and Lachnospiraceae were found to be the most abundant families (7,33).…”

“…The chicken gut microbiota influences nutrient utilization (1,2), immune development (3), endocrine activity (4), development of gastrointestinal tract (5), and detoxification, thus contributing to the improved performance of the birds. The chicken gastrointestinal tract harbors complex communities of bacteria (6,7). However, cecum harbors the most number of commensals and contains up to 10 11 / g organisms (8) and therefore was widely studied.…”

“…Several experiments were conducted previously to study the microbial succession in broiler chicken intestinal tract (7,(13)(14)(15). Also, studies were performed to determine the effect of gut microbes on feed utilization and conversion (1,16).…”

Gut microbiota of a long‐distance migrant demonstrates resistance against environmental microbe incursions

“…Age is an important factor determining gut microbiota composition when young, with chicks having different gut microbiota to adult birds in penguins, kittiwakes and barn swallows (Barbosa et al., ; van Dongen et al., ; Kreisinger et al., ). However, poultry studies suggest that gut microbiota structure resembles that of adults within 0.5–3 months after hatching (Oakley et al., ; Ranjitkar, Lawley, Tannock, & Engberg, ), and studies of two wild migratory shorebird species, Dunlin and Red phalarope, suggest that microbiota diversity stabilizes in 3‐ to 10‐day old chicks (Grond, ). On this basis, and given that both our resident and migrant groups consist of fully grown birds that have completed at least one Siberia‐to‐Australia migration, we do not believe that differences in gut microbiota should exist between second‐year birds at 15 months old and birds that are 3+ years old due to age per se.…”

Spatial variations in intestinal skatole production and microbial composition in broilers

“…However, various factors can affect the bacterial communities in the avian species. The microbial composition of each intestinal segment in broilers is variable (Ranjitkar, Lawley, Tannock, & Engberg, 2016;Torok, Allison, Percy, Ophelkeller, & Hughes, 2011;Wise & Siragusa, 2007), and in the same bowel segment, the results of biological replicates can also vary to different degrees (Sergeant et al, 2014). Zhou et al (2007) suggest that pooling digesta from five birds provides the optimal sample size to examine changes in the composition of microflora using PCR-DGGE profiling techniques.…”