Ruminants trans fatty acids

Gebauer, S. K., Chardigny, J. M, Jakobsen, M. U., Lamarche, B., Lock, A. L, Proctor, S. D Baer, D. J. (2011). Effects of ruminant trans fatty acids on cardiovascular disease and cancer a comprehensive review of epidemiological, clinical, and mechanistic studies. Advance in Nutrition, 2(4), 332-54. 

Bendsen, N. T., Christensen, R., Bartels, E. M. Astrup, A. (2011). Consumption of industrial and ruminant trans fatty acids and risk of coronary heart disease a systematic review and meta-analysis of cohort studies. European Journal of Clinical Nutrition, 65(7), 773-83. 

Some of the fatty acids found in the diets of developed nations (often 1 to 10 g of daily fatty acid intake) are trans fatty acids— fatty acids with one or more double bonds in the trans configuration. Some of these derive from dairy fat and ruminant meats, but the bulk are provided by partially hydrogenated vegetable or fish... 

Small amounts of trans-unsamrated fatty acids are found in ruminant fat (eg, butter fat has 2-7%), where they arise from the action of microorganisms in the rumen, but the main source in the human diet is from partially hydrogenated vegetable oils (eg, margarine). Trans fatty acids compete with essential fatty acids and may exacerbate essential fatty acid deficiency. Moreover, they are strucmrally similar to samrated fatty acids (Chapter 14) and have comparable effects in the promotion of hypercholesterolemia and atherosclerosis (Chapter 26). 

Some of the unsaturated fats ingested by ruminants are partially hydrogenated by bacteria in the rumen. In consequence, milk fat, dairy products, as well as beef and mutton fat, also contain small amounts of trans isomers, about 2 to 9%. However, in fat from ruminants the main trans fatty acid is vaccenic (18 1 t 11), while in hydrogenated fats it is elaidic (18 1 t 9) (Figure 13.14). 

Trans fatty acids The phospholipids in the plasma and in membranes of all cells contain long-chain polynnsatnrated fatty acids (PUFA). During periods of growth and development of organs, PUFAs are reqnired for phospholipid synthesis. The PUFAs are, of conrse, obtained from dietary triacylglycerol and phospholipids. The donble bonds in most natural fatty acids are cis not trans Nonetheless trans fatty acids do occur in dietary fats. If the diet contains trans fatty acids, they might be incorporated into the phospholipids along with the cis fatty acids and hence into membranes. The presence of these abnormal fatty acids will modify the stmctnre of the phospholipids which conld impair the fnnction of the membrane. There are two main sonrces of trans fatty acids in the diet foods produced from ruminants contain trans fatty... 

Bauman, D.E., Lock A.L., Corl B.A., IpC., Salter A.M., Parodi P.W. 2005. Milk fatty acids and human health potential role of conjugated linoleic acid and trans fatty acids. In Ruminant Physiology Digestion, Metabolism and Impact of Nutrition on Gene Expression, Immunology and Stress. (K. Sejrsen, T. Hvelplund, and M.O. Nielsen, eds.), pp. 523-555, Wageningen Academic Publishers, Wageningen, The Netherlands. Academic Publishers. 

The fat in beef, mutton, milk, and cheese contains 2-8% trans fatty acids. These naturally occurring trans fatty acids are formed in the rumen of the stomach (of ruminants) by the action of bacterial enzymes. Most of the trans fatty acids of the diet arise from the industrial hydrogenation of food oils. During this process, most of the unsaturated cis fatty acids are converted to saturated fatty acids, but a fraction is converted to trans fatty acids. In relation to all fatty acids present in the indicated food, salad oils contain 8-17% trans fatty acid, shortening contains 14-60%, and margarines 16-70% (Simopoulos, 1996). Overall, about 6% of our dietary fatty acids are trans fatty acids, where most of these are elaidic acid (McKeigue, 1995). 

Trans-fatty acids also occirr in nature, primarily as a result of bacterial action in the stomach of ruminants. Veal fat contains 2-9% trans-fats. The main somces of trans-fats in the human diet are fast food, cooking oil and margarine. About two thirds of the trans-fatty acids in trans-fats is elaidic acid (Fig. 2.8). 

Griinari, J.M., and Shingfield, K.J. (2002) Effect of Diet on Milk Fat trans Fatty Acid and CLA Isomer Composition in Ruminants, Abstracts of the 93rd AOCS Annual Meeting, AOCS Press, Champaign, IL (Abstr. S2). 

Intake of trans fatty acids is associated with a higher risk of CVD (Aro, 1998). Several countries have introduced mandatory labeling of total trans fatty acids in food products. However, the specific trans fatty acids responsible for the detrimental effects have not been identified nor is it known whether PHVO and ruminant fats present the same risk. Most work has been done using PHVO but, as noted above, ruminant fats have a different distribution. 

Shingfield, K.J., L.Bemard, C. Leroux and Y. Chilliard, 2010. Role of trans fatty acids in the nutritional regulation of mammary lipogenesis in ruminants. Animal, (in press). 

Trans fatty acids present in the diet arise from two origins. The first is from bacterial biohydrogenation in the forestomach of ruminants, which is the source of trans fatty acids present in mutton and beef fats. These are present at a concentration of 2-9% of bovine fat. Trans-11-octadecenoic acid is the main isomer produced although trans-9- and tra s-10-octadecenoic acid are also produced. Thus, trans fatty acids occur in nature and cannot be considered to be foreign substances. 

Trans fatty acids are present in the diet in esterified form, mainly in triacylglycerols but those from ruminant sources may also be present in phospholipids. Before absorption into the body, triacylglycerols must be digested by pancreatic lipase in the upper small intestine. There is no evidence of differences in the hydrolysis and absorption of trans fatty acids, in comparison with that of cis fatty acids. Trans fatty acids are transported from the intestine mainly in chylomicrons, but some are also incorporated into cholesteryl esters and phospholipids. 

In ruminates, replacing soy meal with Camelina meal (2.04 kg of dry matter (DM)) in beef steer diets results in a marked reduction in stress response hormones (Cappellozza et al., 2012). Further, no changes in thyroid function are noted, but this meal reduces acute-phase reactive protein reaction, which is known to increase when cattle are transported or when cattle are introduced to a feedlot setting (Cappellozza et al., 2012). These results are indicative of a positive impact of Camelina meal in reducing stress response in cattle. In dairy cows, Camelina meal (2 kg of DM) results in a marked decrease in milk fat without an impact on total milk production (Hurtaud and Peyraud, 2007). Interestingly, inclusion of Camelina meal results in a marked increase in trans fatty acids, t-10 18 1 and t- 18 1, 11- and 2.6-fold, respectively, and a marked sevenfold increase in c-9, t-11 18 2 (conjugated linoleic acid). This may account for the enhanced spreadabiUty of butter made from milk derived from Camelina meal-fed cows (Hurtaud and Peyraud, 2007). Hence, in a limited number of studies, Camelina meal is observed to have a number of positive effects on the health of cattle, as well as in the parameters associated with milk production and quality. 

Ruminant bacteria produce some trans -unsaturated fatty acids when long-chain fatty acids are synthesised in the bacteria. These are absorbed by the host so that trans-unsaturated fatty acids can be found in adipose tissue and muscle of ruminants. 

The usual diet of ruminants consists of fresh and preserved herbage and cereals. As a result of microbial activity in the rumen, esterified dietary fatty acids are hydrolyzed, short chain fatty acids are produced by fermentation of cellulose and other polysaccharides, unsaturated fatty acids are hydrogenated and/or converted to geometric (trans) and positional isomers, and microbial lipids are synthesized. These activities account in part for the enormous diversity of fatty acids in milk and the unique features short-chain and a high proportion of long chain saturated fatty acids. (Patton and Jensen, 1976 Christie, 1979B). 

BASIC PROTOCOL I PREPARATION OF FATTY ACID METHYL ESTERS FROM LIPID SAMPLES CATALYZED WITH BORON TRIFLUORIDE IN METHANOL In this method, lipid samples are first saponified with an excess of NaOH in methanol. Liberated fatty acids are then methylated in the presence of BF3 in methanol. The resulting fatty acid methyl esters (FAMEs) are extracted with an organic solvent (isooctane or hexane), and then sealed in GC sample vials for analysis. Because of the acidic condition and high temperature (100°C) used in the process, isomerization will occur to those fatty acids containing conjugated dienes, such as in dairy and ruminant meat products, that contain conjugated linoleic acids (CLA). If CLA isomers are of interest in the analysis, Basic Protocol 2 or the Alternate Protocol should be used instead. Based on experience, this method underestimates the amount of the naturally occurring cis-9, trans-11 CLA isomer by -10%. The formulas for the chemical reactions involved in this protocol are outlined in Equation D1.2.1 Saponification RCOO-R + NaOH, RCOO-Na + R -OH v 100°C DC Esterification RCOO-Na + CH,OH r 3 v RCOO-CH, + NaOH ioo°c ... 

This unit describes the attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic method (AOCS, 1999a AOAC International, 2000), a novel method for measuring the total amount of fat with isolated trans double bonds. It is applicable to natural fats (ruminant fats) and processed fats and oils (partially hydrogenated fats and oils or refined vegetable oils) consisting of long-chain fatty acid methyl esters or triacylglycerols with trans levels >5%, as percent of total fat (AOAC International, 2000). 

Chilliard, Y., Ferlay, A., Mansbridge, R.M. and Doreau, M. (2000) Ruminant milk fat plasticity nutritional control of saturated, polyunsaturated, trans and conjugated fatty acids. Ann. Zootech., 49, 181-205. 

Table 3.2. Range of double bond positions in trans Cisu and conjugated Cis 2 fatty acids and their ruminal outflow in growing and lactating cattle ...

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