DIFFERENCES IN METABOLISM OF ESTERIFIED AND UNESTERIFIED LINOLEIC ACID BY RUMEN MICRO-ORGANISMS

1. Sheep were given intraruminal infusions of maize oil or linoleic acid and samples of contents were taken from the rumen and abomasum at different times after the infusions. Hydrolysis of the maize oil occurred in the rumen with the production of mono- and di-glycerides as intermediates. Linoleic acid derived from the maize oil was hydrogenated to stearic acid. When linoleic acid was infused into the rumen, little or no stearic acid was produced and octadecenoic acid accumulated. 2. When linoleic acid or maize oil was incubated with rumen contents in an artificial rumen and samples of the reaction mixtures were taken from the apparatus after various time intervals, the results were similar to those obtained in vivo, except that the hydrolysis of maize oil did not give rise to mono- and di-glycerides. 3. These results are discussed in relation to previous findings on the effects of intraruminal infusions of maize oil or linoleic acid on the fatty acid composition of the blood triglycerides of sheep. © 1969, The Nutrition Society. All rights reserved.