Conjugated linoleic acid is synthesized endogenously in lactating dairy cows by Delta(9)-desaturase.
J. M. Griinari,Benjamin A. Corl,Shannon H. Lacy,P. Y. Chouinard,K. V. V. Nurmela,Dale E. Bauman +5 more
TLDR
Results demonstrate that endogenous synthesis of CLA from trans-11 18:1 represented the primary source of CLA in milk fat of lactating cows.Abstract:
Conjugated linoleic acid (CLA) is a naturally occurring anticarcinogen found in milk fat and body fat of ruminants. Although CLA is an intermediate in ruminal biohydrogenation of linoleic acid, we hypothesized that its primary source was from endogenous synthesis. This would involve Delta(9)-desaturase and synthesis from trans-11 18:1, another intermediate in ruminal biohydrogenation. Our first experiment supplied lactating cows (n = 3) with trans-11 18:1 by abomasal infusion and examined the potential for endogenous synthesis by measuring changes in milk fat CLA. By d 3, infusion of trans-11 18:1 resulted in a 31% increase in concentration of cis-9, trans-11 CLA in milk fat, demonstrating that an active pathway for endogenous synthesis of CLA exists. Our second experiment examined the quantitative importance of endogenous synthesis of CLA in lactating cows (n = 3) by abomasally infusing a putative stimulator (retinol palmitate) or an inhibitor (sterculic oil) of Delta(9)-desaturase. Infusion of retinol palmitate had no influence on milk fatty acid desaturation, and yield of CLA in milk fat was not altered. However, sterculic oil infusion decreased the concentration of CLA in milk fat by 45%. Consistent with Delta(9)-desaturase inhibition, the sterculic oil treatment also altered the milk fat concentration of other Delta(9)-desaturase products as indicated by the two- to threefold increase in the ratios of 14:0 to 14:1(,) 16:0 to 16:1 and 18:0 to cis-18:1. Using changes in the ratio of 14:0 to 14:1 as an indication of the extent of Delta(9)-desaturase inhibition with the sterculic oil treatment, an estimated 64% of the CLA in milk fat was of endogenous origin. Overall, results demonstrate that endogenous synthesis of CLA from trans-11 18:1 represented the primary source of CLA in milk fat of lactating cows.read more
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Journal ArticleDOI
Effect of diets rich in N-3 polyunsatured fatty acids on muscle lipids and fatty acids in Belgian Blue double-muscled young bulls.
TL;DR: The results show that the fatty acid composition of the feed during the earlier periods of life of the animal were important and influenced the final intramuscular fatty acid compositions of bulls at slaughter.
Journal ArticleDOI
Effect of fish oil on in vitro rumen lipolysis, apparent biohydrogenation of linoleic and linolenic acid and accumulation of biohydrogenation intermediates
TL;DR: Addition of FO to diets containing C18:2n-6 or C 18:3n-3 could increase ruminal accumulation and, hence, duodenal flow of t11C18:1, which could result in a higher uptake by the tissues and more substrate for the endogenous synthesis of c9t11CLA.
Journal ArticleDOI
Importance of functional ingredients in yak milk-derived food on health of Tibetan nomads living under high-altitude stress: a review.
Xusheng Guo,Ruijun Long,Michael Kreuzer,Luming Ding,Zhanhuan Shang,Ying Zhang,Yang Yang,Guangxin Cui +7 more
TL;DR: It is proposed that the Tibetan nomads have developed a nutritional mechanism adapted to cope with the specific challenges posed by the environment of the world's highest plateau.
Journal ArticleDOI
Conjugated linoleic acid content of beef from cattle fed diets containing high grain, CLA, or raised on forages
TL;DR: Raising cattle on forage and pasture with no grain supplementation enhances beef CLA content and finishing cattle on pasture increased the vitamin E content of beef by 300% compared to beef from animals finished on a traditional high-grain diet.
Book ChapterDOI
Conjugated Linoleic Acid: Biosynthesis and Nutritional Significance
Dale E. Bauman,Adam L. Lock +1 more
TL;DR: The term conjugated linoleic acid (CLA) refers to a mixture of positional and geometric isomers of CLA with a conjugation double-bond system as discussed by the authors.
References
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TL;DR: In this article, an improved method for quantifying linoleic acid (CLA) in food was developed, which was used to produce a data base of more than 90 food items including meat, poultry, seafood, dairy products, plant oils, and infant and processed foods.
Journal ArticleDOI
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Journal ArticleDOI
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