|Wells, James - Jim|
|FOOTE, ANDREW - Former ARS Employee|
Submitted to: Congress on Gastrointestinal Function
Publication Type: Abstract Only
Publication Acceptance Date: 2/28/2019
Publication Date: 3/7/2019
Citation: Freetly, H.C., Wells, J., Dickey, A., Lindholm-Perry, A., Keele, J., Foote, A. 2019. Digestive tract microbiota of beef cattle that differed in feed efficiency [abstract]. 2019 Congress on Gastrointestinal Function, April 15-17, 2019, Chicago, IL. p. 41-42.
Technical Abstract: We hypothesized cattle that differed in body weight gain (BW) had different digestive tract microbiota. Sixty-six steers (age = 396 ± 1 d; BW = 456 ± 5 kg) were individually fed for 84 d. Steers received a ration that as dry matter consisted of 8.0% chopped alfalfa hay, 20% wet distillers grain with solubles, 67.75% dry-rolled corn, and 4.25% vitamin/mineral mix. The vitamin/ mineral mix included 772 mg/kg monensin. The 8 steers with the greatest (2.39 ± 0.06 kg/d) and 8 steers with the least average daily gain (1 .85 ± 0.06 kg/d) that were within ± 0.55 SD of the mean (11.9 ± 0.1 kg/d) dry matter intake were selected for the study. At slaughter, digesta was collected from the rumen, duodenum, jejunum, ileum, cecum, and colon. Total DNA was isolated and amplicon library preparation was performed by PCR amplification of the V1 to V3 region of the 16S rRNA gene. Libraries were sequenced with a 600-cycle V2 kit with 300bp paired-end reads on an lllumina MiSeq next-generation sequencer. Operational taxonomic units (OTU) were classified using 0.03 dissimilarity and identified using the Greengenes 16S rRNA Gene Database. Chao1, Shannon, Simpson, and lnvSimpson diversity indexes and PERMANOVA between steer classifications groups did not differ (P > 0.05) for the rumen, duodenum, ileum, cecum, and colon. In the jejunum, there tended to be a difference (P < 0.1) in the Chao1and Simpson diversity indexes between steer classifications, but there was no difference in the Shannon and lnvSimpson diversity indexes. Classification groups differed (P = 0.006) in the PERMANOVA. The hierarchical dependence false discovery rate procedure returned 9 clades as being differentially abundant between steer classifications (P < 0.05). The majority of the OTU were in the families Coriobacteriaceae and Veillonellaceae. This study suggests that intestinal differences in microbiota of ruminants may be associated with animal performance.