This is a draft schedule. Presentation dates, times and locations may be subject to change.
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Effects of the Seaweed Ascophyllum Nodosum on the Rumen Microbiome and Fecal Pathogenic Escherichia coli Serotypes in Sheep
Effects of the Seaweed Ascophyllum Nodosum on the Rumen Microbiome and Fecal Pathogenic Escherichia coli Serotypes in Sheep
Tuesday, July 11, 2017
Exhibit Hall (Baltimore Convention Center)
Feeding rams Tasco® (SW), a high quality, sun-dried seaweed meal produced from the brown macroalga Ascophyllum nodosum, reduced Escherichia coli O157:H7 shedding in feces without affecting rumen fermentation. The effects of SW on the microbiota and other pathogenic E. coli O-serotypes in the rumen have not been extensively studied. The current study aimed to evaluate the effects of Tasco® at different feeding levels on the rumen microbiome as well as the presence of non-O157E. coli serotypes. A 4×4 Latin square design used 8 ram lambs randomly allocated to diets containing 0%, 1%, 3%, or 5% of the diet DM as SW. Rumen contents and feces were collected and DNA was extracted and 16S rRNA was sequenced to study the ecology of bacterial and archaeal communities using QIIME. Functional pathways were predicted using PICRUSt and seven E. coli serotypes were measured using multiplex PCR. Feeding SW linearly (P < 0.001) lowered the total rumen bacterial population (log10 16S rRNA gene copies/g) from11.63 in Con to approximately 10.50, and linearly reduced (P < 0.001) the total archaeal population from 8.70 to 8.13. Different SW levels did not affect the overall bacterial and archaeal profiles or the microbial diversity indices, with substantial variation in these parameters among individual rams. Relative abundance of three bacteria phyla, five bacteria families, and seven species differed among SW levels. There were 14 enriched metabolic pathways in SW-fed rams, while only 3 pathways were suppressed by SW feeding. A VFA profile with higher acetate molar portion (P < 0.001) and lower propionate (P < 0.001) and butyrate (P < 0.001) molar portion was seen with SW supplement, and the lower butyrate can be associated with the enrichment of ‘Butanate metabolism’ pathway in the SW-fed rams. Total E. coli population within the rumen was linearly reduced (P < 0.001) by SW from 6.82 (log10 16S rRNA gene copies/g) in Con to 6.27, 5.86, and 5.90 with the three SW levels. Including SW only completely eliminated O121 in the rumen and the feces, but O45, O103, and O111 were also eliminated in the feces although they were detected in the rumen.