Identification and Ruminal Outflow of Long-Chain Fatty Acid Biohydrogenation Intermediates in Cows Fed Diets Containing Fish Oil

摘要: The abundance of 20- to 24-carbon fatty acids in omasal digesta cows fed grass silage-based diets supplemented with 0 (Control) and 250 g/day fish oil (FO) was examined investigate the fate long-chain unsaturated rumen. Complimentary argentation thin-layer chromatography gas-chromatography mass-spectrometry analysis acid methyl esters corresponding 4,4-dimethyloxazoline derivatives prepared from enabled structure novel 22-carbon be elucidated. Compared Control, FO treatment resulted formation accumulation 27 biohydrogenation intermediates containing at least one trans double bond appearance cis-14 20:1, 20:2n-3, 21:4n-3 22:3n-6 not contained oil. No conjugated ≥20-carbon were detected Control or digesta. In conclusion, diet results numerous rumen lactating cows. Comparison intake flow 20-, 21- omasum treatments suggests that first committed steps 20:5n-3, 21:5n-3 22:6n-3 hydrogenation involve reduction and/or isomerisation bonds closest carboxyl group.