Effects of Concentrate to Roughage Ratio on the Formation of cis9, trans11-CLA and trans11-Octadecenoic Acid in Rumen Fluid and Plasma of Sheep When fed High Oleic or High Linoleic Acid Oils

Wang, J. H.; Choi, S. H.; Song, M. K.

doi:2003.16.11.1604

Article

Animal Breeding and Genetics

Asian-Australasian Journal of Animal Sciences 2003;16(11): 1604-1609.
https://doi.org/10.5713/ajas.2003.1604 Published online January 1, 2003.

Effects of Concentrate to Roughage Ratio on the Formation of cis9, trans11-CLA and trans11-Octadecenoic Acid in Rumen Fluid and Plasma of Sheep When fed High Oleic or High Linoleic Acid Oils

J. H. Wang, S. H. Choi, M. K. Song

Abstract

A metabolism trial with four ruminally fistulated sheep was conducted in a 4횞4 Latin square design to examine the effect of concentrate to roughage ratio (70:30 vs. 85:15) and oil source (soybean oil vs. rapeseed oil) on the ruminal fermentation pattern and C18-fatty acids composition including trans11-C18:1 (trans11-ODA) and cis9, trans11-18:2 (cis9, trans11-CLA) in the rumen fluid and plasma. Oil was added to the concentrate at 5% level of the total diet (DM basis) and chopped rye grass hay was fed as roughage. An increased level of concentrate (85%) within supplemented oil slightly lowered pH but increased ammonia concentration. Supplementation of rapeseed oil relatively increased pH and ammonia concentration. Higher concentrate level resulted in increased tendencies of total VFA concentration while oil source did not affect the total VFA concentration and VFA proportion. Whole tract digestibilities of DM, CP, EE, NDF and OM in diets slightly increased at higher concentrate level. Proportions of oleic acid (C18:1) and linoleic acid (C18:2) in the rumen fluid were influenced by the fatty acid composition of oil source but oil source did not affect the in vitro formations of trans11-ODA and cis9, trans11-CLA. Slightly increased trans11-ODA and cis9, trans11-CLA proportions, however, were observed from the sheep fed high roughage diet supplemented with both soybean oil and rapeseed oil. The C18:1 and C18:2 composition in supplemented oils responded to those in plasma of sheep. Effects of concentrate to roughage ratio and oil source on trans11-ODA and cis9, trans11-CLA proportions in plasma were found to be small. Proportion of cis9, trans11-CLA in plasma tended to be increased from the sheep fed high roughage diet and collection time at 9h post feeding.

Keywords: Concentrate to Roughage Ratio; Oil Source; Cis9; trans11-C18:2; Trans11-C18:1; Sheep