IMPACT OF DIETARY TANNINS ON RUMEN MICROBIOTA IN BOVINE

DIAZ-CARRASCO, JM; CABRAL, C; REDONDO, L M; PIN VISO, N; FARBER, M; FERNANDEZ MIYAKAWA, ME

Paris

Simposio; 2nd International Symposium on Alternatives to Antibiotics: Challenges and Solutions in Animal Production; 2016

OIE - USDA

Tannins added in the diet are being used to improve nutrition and to control enteric diseases in farmanimals and appear to be a promising alternative to antibiotic growth promoters. In previous studieswe found that tannins have antibacterial activity against Clostridium perfringens and are effectivefor long periods of time and prevent these anaerobic bacteria to develop resistance. Many reportsindicate that inclusion of tannins in feed can improve performance and health in ruminants. It isspeculated that tannins modify the digestive process not only by binding dietary protein but also throughmodulation of gastrointestinal microbiota. Our aim was to evaluate in vivo the impact of SilvaFeedRBM, a blend of tannins specifically designed with the aim of optimizing the ruminal microbiota. Therumen microbiota composition and its interplay with rumen physiological parameters were studiedat different times in fistulated steers. High-throughput sequencing of 16S rRNA gene (Illumina MiSeqplatform) was used to analyze the effects of SilvaFeed RBM in rumen microbiota of six HolandoArgentinosteers. A total of 9.871.395 sequences were obtained at five time points (0, 3, 5, 9 and12 days after tannins supplementation). Bacterial diversity estimators tended to homogenize throughtannins treatment and dysbiotic microbiota profiles were normalized. Firmicutes to Bacteroidetes ratio,a parameter linked to energy harvesting function in mammals, was gradually increased by tanninsover time, mainly by favoring members of family Ruminococcaceae in detriment of genus Prevotella.Other fibrolytic, amylolytic and ureolytic bacteria were also modulated by tannins and methanogenicarchaea were inhibited. Concomitantly, ruminal pH was significantly increased and remained stableuntil the end of the experiment. Our results suggest a link between microbiota normalization andruminal physiology stabilization. More studies are required in order to evaluate tannins potential toefficiently and reproducibly improve ruminant nutrition and health.