Understanding the mechanisms of zinc bacitracin and avilamycin on animal production: linking gut microbiota and growth performance in chickens

• Published in: Applied microbiology and biotechnology Vol. 101; no. 11; pp. 4547 - 4559
• Main Authors: Crisol-Martínez, Eduardo, Stanley, Dragana, Geier, Mark S., Hughes, Robert J., Moore, Robert J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-06-2017; Springer; Springer Nature B.V
• Subjects: Abundance; Agronomy; Animal Feed - analysis; Animal production; Animals; Anti-Bacterial Agents - adverse effects; Anti-Bacterial Agents - pharmacology; Antibiotics; Applied Genetics and Molecular Biotechnology; Bacitracin; Bacitracin - adverse effects; Bacitracin - pharmacology; Bacteria; Bacteria - classification; Bacteria - drug effects; Bacteria - genetics; Biodiversity; Biomedical and Life Sciences; Biotechnology; Cecum - drug effects; Cecum - microbiology; Chickens; Chickens - growth & development; Chickens - microbiology; Conversion ratio; Dominant species; Feed conversion; Gastrointestinal Microbiome - drug effects; Gene sequencing; Group dynamics; Intestinal microflora; Lactobacilli; Lactobacillus - drug effects; Life Sciences; Microbial Genetics and Genomics; Microbiology; Microbiota; Microbiota (Symbiotic organisms); Microorganisms; Oligosaccharides - adverse effects; Oligosaccharides - pharmacology; Physical growth; Poultry; Probiotics; Ribonucleic acid; RNA; RNA, Ribosomal, 16S; rRNA 16S; Taxa; Zinc; Zinc bacitracin; Productivity; Microbiota; Gastrointestinal tract; Antibiotics; Caecum
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-017-8193-9

Unravelling the mechanisms of how antibiotics influence growth performance through changes in gut microbiota can lead to the identification of highly productive microbiota in animal production. Here we investigated the effect of zinc bacitracin and avilamycin on growth performance and caecal microbiota in chickens and analysed associations between individual bacteria and growth performance. Two trials were undertaken; each used 96 individually caged 15-day-old Cobb broilers. Trial 1 had a control group (
n =
 48) and a zinc bacitracin (50 ppm) treatment group (
n =
 48). Trial 2 had a control group (
n =
 48) and an avilamycin (15 ppm) treatment group (
n =
 48). Chicken growth performance was evaluated over a 10-day period, and caecal microbiota was characterised by sequencing of bacterial 16S rRNA gene amplicons. Avilamycin produced no effect on growth performance and exhibited little significant disturbance of the microbiota structure. However, zinc bacitracin reduced the feed conversion ratio (FCR) in treated birds, changed the composition and increased the diversity of their caecal microbiota by reducing dominant species. Avilamycin only produced minor reductions in the abundance of two microbial taxa, whereas zinc bacitracin produced relatively large shifts in a number of taxa, primarily
Lactobacillus
species. Also, a number of phylotypes closely related to lactobacilli species were positively or negatively correlated with FCR values, suggesting contrasting effects of
Lactobacillus
spp. on chicken growth performance. By harnessing such bacteria, it may be possible to develop high-productivity strategies in poultry that rely on the use of probiotics and less on in-feed antibiotics.