Effect of feeding different flaxseed-based products on the rumen microbial community of dairy cows evaluated by high-throughput DNA sequencing

• Published in: Journal of animal science 2016-10, Vol.94, p.796-796
• Main Authors: Castillo-Lopez, E, Moats, J, Aluthge, N D, Ramirez Ramirez, H A, McAllister, T A, Anderson, C L, Christensen, D A, Mutsvangwa, T, Lee-Rangel, H, Penner, G B, Fernando, S C
• Format: Article
• Language: English
• Subjects: Alfalfa; Bacteria; Barley; Beans; Broad beans; Cattle; Clostridium; Dairy cattle; Dehydration; Deoxyribonucleic acid; Diet; DNA; DNA sequencing; Extrusion; Feeding; Flax; Genera; Microorganisms; Peas; Phylogenetics; Phylogeny; rRNA 16S; Rumen; Tannins; Taxa; Vegetables; Vicia faba
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jam2016-1635

Four ruminally-cannulated lactating Holstein cows (mean and SD, 116.5 ± 17.5 DIM; 712.7 ± 92.3 kg BW) were used in a 4 x 4 Latin square with 28-d experimental periods to evaluate the effect of feeding flaxseed-based products on the rumen microbial population. Treatments (DM basis) were: 1) CONT, a control diet containing 51.9% of a barley-based concentrate, 20.0% alfalfa hay, and 28.2% barley silage; 2) FLAX, inclusion of 11.4% of a non-extruded flaxseed-based product which contained 55% flaxseed, 37% field peas, and 6.8% dehydrated alfalfa; 3) EF, inclusion of 11.4% of an extruded flaxseed-based product which contained 55% flaxseed, 37% field peas, and 6.8% dehydrated alfalfa; and 4) EFT, inclusion of 11.4% of an extruded flaxseed-based product which contained 55% flaxseed, 37% high-tannin faba beans (Vicia faba), and 6.8% dehydrated alfalfa. The flaxseed-based products used in FLAX, EF, and EFT were included (3 kg/d) by partially replacing 3 kg/d of the barley-based concentrate. At the end of each period, samples of ruminal contents were collected and DNA was extracted from samples. The V3 hypervariable region of the 16S rRNA bacterial gene was amplified and sequenced. Sequenced reads were subjected to phylogenetic classification using the pipelines UPARSE and QIIME. Data for the abundance of bacterial taxa were analyzed using the MIXED procedure of SAS. Major bacterial phyla were not affected (P = 0.34) by diet and included Bacteroidetes (48.8 ± 3.66%), Firmicutes (46.0 ± 3.92%), and Proteobacteria (1.3 ± 0.30%). Major bacterial families were similar (P = 0.71) across diets and were represented by Prevotellaceae (20.2 ± 2.82%) and Veillonellaceae (16.3 ± 6.19%). In addition, major genera remained unaffected (P ≥ 0.38) and included Prevotella (19.3 ± 2.47%) and Succiniclasticum (14.5 ± 6.12%). However, compared to CONT, there were shifts in some bacterial families and genera for EF and EFT. The biohydrogenating bacteria, Clostridium, decreased (P < 0.01) resulting in 0.4, 0.1, 0.1, and 0.2 ± 0.05% for CONT, FLAX, EF, and EFT, respectively. Flaxseed extrusion and high-tannin faba beans did not affect predominant bacterial taxa; however, there were shifts in less abundant taxa including a decrease in the biohydrogenating genus Clostridium.