title: Dietary fish oil supplements modify ruminal biohydrogenation, alter the flow of fatty acids at the omasum, and induce changes in the ruminal Butyrivibrio population in lactating cows.
abstract: Four lactating cows fitted with ruminal cannulae and fed a grass silage-based diet were used in a 4 × 4 Latin square with 28-d periods to investigate the effects of incremental dietary fish oil (FO) supplementation (0, 75, 150, or 300 g/d) on the flow of fatty acids at the omasum and populations of rumen bacteria capable of biohydrogenation. FO decreased silage intake and ruminal volatile fatty acid concentrations and promoted an increase in molar butyrate and propionate proportions at the expense of acetate. Extensive ruminal biohydrogenation of 20:5(n-3) and 22:6(n-3) resulted in corresponding increases in numerous 20- and 22-carbon unsaturated fatty acids at the omasum. Omasal flow of several 20-, 21-, and 22-carbon all-cis (n-3) PUFA exceeded the intake from FO. Supplements of FO also induced a dose-dependent decrease in 18:0 and increased trans 18:1 and trans 18:2 flow at the omasum. Trans-11 was the major 18:1 intermediate in digesta, while FO induced quadratic increases in trans-10 18:1 flow, reaching a maximum of 300 g/d. FO had no substantial influence on omasal flow of CLA. Results suggest that one or more fatty acids in FO inhibit the reduction of trans-18:1 and trans-18:2 intermediates by ruminal microorganisms. qPCR based on 16S rRNA genes in omasal digesta indicated that key Butyrivibrio spp. declined linearly in response to FO. Dose-dependent increases in ruminal outflow of biohydrogenation intermediates containing one or more trans double bonds in response to FO has major implications for host metabolism and the nutritional quality of ruminant foods.
authors: Animal Production Research, MTT Agrifood Research Finland, Jokioinen, Finland. kevin.shingfield@mtt.fi
authors: Kevin J
authors: KJ
authors: Shingfield
authors: Piia
authors: P
authors: Kairenius
authors: Anu
authors: A
authors: Arölä
authors: Delphine
authors: D
authors: Paillard
authors: Stefan
authors: S
authors: Muetzel
authors: Seppo
authors: S
authors: Ahvenjärvi
authors: Aila
authors: A
authors: Vanhatalo
authors: Pekka
authors: P
authors: Huhtanen
authors: Vesa
authors: V
authors: Toivonen
authors: J Mikko
authors: JM
authors: Griinari
authors: R John
authors: RJ
authors: Wallace
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D045856:Butyrivibrio / Q000145:classification / Q000187:drug effects*; D002417:Cattle / Q000382:microbiology* / Q000502:physiology; D018592:Cross-Over Studies; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D005395:Fish Oils / Q000737:chemistry / Q000494:pharmacology*; D007774:Lactation / Q000502:physiology*; D009851:Omasum / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012417:Rumen / Q000187:drug effects / Q000382:microbiology; D012680:Sensitivity and Specificity
chemical_list: D005227:Fatty Acids; D005395:Fish Oils