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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Incremental amounts of ground flaxseed decrease milk yield but increase n-3 fatty acids and conjugated linoleic acids in dairy cows fed high-forage diets1
T. L. Resende,Jana Kraft,Kathy J. Soder,A. B. D. Pereira,D. E. Woitschach,Ronaldo Braga Reis,Andre F. Brito +6 more
TL;DR: The diet with 15% GFX supplementation resulted in the lowest milk yield but highest milk proportions and yields of cis-9,trans-11 18:2 and n-3 FA, and apparent total-tract digestibilities of nutrients either decreased (dry matter) or tended to decrease linearly in cows fed GFX.
Journal ArticleDOI
Milk production and fatty acid profile of milkfat by dairy cows fed a winter oats (Avena sativa L.) pasture only or a total mixed ration
TL;DR: In this paper, the authors compared 12 Holstein dairy cows in mid-lactation fed winter oats pasture only (WOP) or total mixed ration (TMR) in a single crossover design, and found that cows fed WOP lost liveweight and body condition score, but the cows fed TMR gained liveweight.
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Effects of sunflower seed inclusion in finishing diets for steers on performance, carcass characteristics, muscle and adipose fatty acid composition and meat quality
TL;DR: Supplementation of finishing diets for steers with SFS increased content of CLA isomers and vaccenic acid in tissues, without affecting feed conversion efficiency or meat quality, especially when incorporated into silage-free diets.
Journal ArticleDOI
Os efeitos do ácido linoléico conjugado no metabolismo animal: avanço das pesquisas e perspectivas para o futuro
Lilia Ferreira Santos-Zago,Lilia Ferreira Santos-Zago,Adriana Prais Botelho,Admar Costa de Oliveira +3 more
TL;DR: There is strong indication that the action of this conjugated fatty acid on a class of transition factors - the peroxisome proliferator-activated receptor - and on the consequent modulation of gene expression can be the fundamental explanation of its physiological effects.
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The effects of bovine milk fat on human health
Jan Miciński,Grzegorz Zwierzchowski,Ireneusz M. Kowalski,Józef Szarek,Boguslaw Pierozynski,Juozas Raistenskis +5 more
TL;DR: A literature review of the health effects of components found in bovine milk fat and its effects on human health concludes that a growing tendency to replace animal fats, mainly milk fat, with vegetable fats is a matter of concern.
References
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TL;DR: In this article, the authors present official methods of analysis of AOAC International, official methods for analysis of aOAC-related project, and a set of methods for the analysis of their work.
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Dietary sources of conjugated dienoic isomers of linoleic acid, a newly recognized class of anticarcinogens
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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