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Targets and procedures for altering ruminant meat and milk lipids

Published online by Cambridge University Press:  28 February 2007

D. Demeyer  and
M. Doreau
D. Demeyer*
Affiliation:
Department of Animal Production and Department of Nutrition and Food Technology, University of Gent, Proefhoevestraat 10, 9090 Melle, Belgium
M. Doreau
Affiliation:
Ruminant Undernutrition Laboratory, Institut National de la Recherche Agronomique, Theix, 63122 Saint-Genès-Champanelle, France
*
*Corresponding Author: Professor D. Demeyer, fax +32 9 264 9099, email Daniel.Demeyer@mug.ac.uk
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Abstract

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Beef and dairy products suffer from a negative health image, related to the nature of their lipid fraction. Rumen lipid metabolism involves the presence of saturated lipids in ruminant tissues. Lipolysis, fatty acid biohydrogenation and formation of microbial fatty acids in the rumen and their effects on rumen outflow of fatty acids are discussed. Special emphasis is given to the formation of trans-fatty acids and the possibilities of decreasing biohydrogenation. Small differences in intestinal digestibilities of fatty acids are mentioned, followed by a discussion on transfer of absorbed fatty acids into milk and adipose tissue lipids. The preferential retention of polyunsaturated fatty acids as well as the balance between synthesis and incorporation of fatty acids in tissues is described. Dietary means for the modification of milk fat are listed, with special emphasis on the possibilities for enrichment in polyunsaturated fatty acids and the presence of conjugated linoleic acids. A description of the nature and development of fat depots in beef cattle is followed by a discussion of breed, conformation and feed effects on adipose tissue distribution and fatty acid composition. Special emphasis is given to the very lean Belgian Blue double-muscled breed. The review ends with a consideration of the limits to the modification of ruminant fats, involving considerations of consumer acceptance as well as animal welfare and environmental effects.

Keywords

Beef and dairy productsRuminant fatsPolyunsaturated fatty acidsBelgian Blue double-muscled cattle
Type
Symposium on ‘Food technology: can it alter the functionality of nutrients’
Information
Proceedings of the Nutrition Society , Volume 58 , Issue 3 , August 1999 , pp. 593 - 607
Copyright
Copyright © The Nutrition Society 1999

References

Armstrong, JD & Spears, JW (1988) Intravenous administration of ionophores in ruminants: effects on metabolism independent of the rumen. Journal of Animal Science 66, 1807–1817.CrossRefGoogle Scholar
Ashes, JR, Fleck, E & Scott, TW (1995) Dietary manipulation of membrane lipids and its implication for their role in the production of second messengers. In Ruminant Physiology: Digestion, Metabolism, Growth and Reproduction, pp. 373–386 van Engelhardt, W, Leonhard-Marek, S, Breves, G and Giesecke, D, editors Stuttgart: Ferdinand Enke Verlag.Google Scholar
Ashes, JR, Siebert, BD, Gulati, SK, Cuthbertson, AZ & Scott, TW (1992) Incorporation of n−3 fatty acids of fish oil into tissue and serum lipids of ruminants. Lipids 27, 629–631.Google Scholar
Baer, RJ (1996) Production and utilisation of dairy cow’s milk and products with increased unsaturated fatty acids. In Progress in Dairy Science, pp. 247–261 [Phillips, CJC, editor]. New York: CAB International.Google Scholar
Bauchart, D, Legay-Carmier, F, Doreau, M & Gaillard, B (1990) Lipid metabolism of liquid-associated and solid-adherent bacteria in rumen contents of dairy cows offered lipid-supplemented diets. British Journal of Nutrition 63, 563–578.CrossRefGoogle ScholarPubMed
Bayard, CC & Wolff, RL (1996) Analysis of trans−18 : 1 isomer content and profile in edible refined beef tallow. Journal of the American Oil Chemists Society 73, 531–533.CrossRefGoogle Scholar
Belury, MA (1995) Conjugated dienoic linoleate: a polyunsaturated fatty acid with unique chemoprotective properties. Nutrition Reviews 53, 83–99.CrossRefGoogle ScholarPubMed
Brockerhoff, H (1966) Fatty acid distribution patterns of animal depot fats. Comparative Biochemistry and Physiology 19, 1–12.CrossRefGoogle ScholarPubMed
Butantu, M (1996) La supplémentation lipidique chez la vache laitière (Lipid supplementation in dairy cows). PhD Thesis, University of Louvain-la-Neuve, France.Google Scholar
Cant, JP, Fredeen, AH, MacIntyre, T, Gunn, J & Crowe, N (1997) Effect of fish oil and monensin on milk composition in dairy cows. Canadian Journal of Animal Science 77, 125–131.Google Scholar
Chalupa, W, Calligan, DT & Ferguson, JD (1996) Animal nutrition and management in the 21st century. Animal Feed Science and Technology 58, 1–18.CrossRefGoogle Scholar
Chilliard, Y, Chardigny, JM, Chabrot, J, Ollier, A, Sebedio, J-L & Doreau, M (1999) Effects of ruminal or postruminal fish oil supply on conjugated linoleic acid (CLA) content of cow milk fat. Proceedings of the Nutrition Society 58, 70A.Google Scholar
Chouinard, PY, Corneau, L, Bauman, DE, Butler, WR, Chilliard, Y & Drackley, K (1998 a) Conjugated linoleic acid content of milk from cows fed different sources of dietary fat. Journal of Dairy Science 81, Suppl. 1, 233.Google Scholar
Chouinard, PY, Corneau, L, Bauman, DE, Metzger, LE & Barbano, DM (1998 b) Milk yield and composition during abomasal infusion of conjugated linoleic acid in dairy cows. Journal of Dairy Science 81, Suppl. 1, 353.Google Scholar
Chouinard, PY, Girard, V & Brisson, GJ (1997) Performance and profiles of milk fatty acids of cows fed full fat, heat-treated soybeans using various processing methods. Journal of Dairy Science 80, 334–342.CrossRefGoogle ScholarPubMed
Christie, WW (editor) (1981) The composition, structure and function of lipids in the tissues of ruminant animals. In Lipid Metabolism in Ruminant Animals, pp. 95–191. Oxford: Pergamon Press.CrossRefGoogle Scholar
Claus, R (1991) Meat and consumer preferences in Europe: demography, marketing issues. In The European Meat Industries in the 1990’s, pp. 217–246 [Smulders, FJM, editor]. Utrecht: ECCEAMST.Google Scholar
Clinquart, A, Istasse, L, Dufrasne, I, Mayombo, A, Van Eenaeme, C & Bienfait, J-M (1991) Effects on animal performance and fat composition of two fat concentrates in diets for growing-fattening bulls. Animal Production 53, 315–320.Google Scholar
Clinquart, A, Micol, D, Brundseaux, C, Dufrasne, I & Istasse, L (1995) Utilisation des matières grasses chez les bovins l’engraissement (Utilization of fat concentrates for fattening cattle). INRA Productions Animales 8, 29–42.CrossRefGoogle Scholar
Corl, BA, Chouinard, PY, Bauman, DE, Dwyer, DA, Griinari, JM & Nurmela, KV (1998) Conjugated linoleic acid in milk fat of dairy cows originates in part by endogenous synthesis from trans-11 octadedenoic acid. Journal of Dairy Science 81, Suppl. 1, 233.Google Scholar
Deffense, E (1993) Milk fat fractionation today: a review. Journal of the American Oil Chemists Society 70, 1193–1201.CrossRefGoogle Scholar
Demeyer, D (1973) Lipidstoffwechsel im Pansen (Lipid metabolism in the rumen). In Biologie und Biochemie der Mikrobiellen Verdauung (Biology and Biochemistry of Microbial Digestion), pp. 209–234 [Giesecke, D and Henderickx, H, editors]. Munchen: BL Verslaggesellschaft.Google Scholar
Demeyer, D (1997) An introduction to the OECD programme: meat quality and the quality of animal production. Food Chemistry 59, 491–497.CrossRefGoogle Scholar
Demeyer, D, Buysse, G & Fiems, L (1995 a) Meat quality in double muscled animals. In Composition of Meat in Relation to Processing, Nutritional and Sensory Quality, pp. 95–102 [Lundström, K, Hansson, I and Wiklund, E, editors]. Utrecht: ECCEAMST.Google Scholar
Demeyer, D & Van Nevel, C (1995) Transformations and effects of lipids in the rumen: three decades of research at Gent University. Archives of Animal Nutrition 48, 119–134.Google ScholarPubMed
Demeyer, D, Van Nevel, C & Fiems, L (1995 b) Nutritional engineering of beef fat composition: motive, target and approach. In Composition of Meat in Relation to Processing, Nutritional and Sensory Quality, pp. 15–36[Lundström, K, Hansson, I and Wiklund, E, editors]. Utrecht: ECCEAMST.Google Scholar
Demeyer, DI, Henderson, C & Prins, R (1978) Relative significance of exogenous and de novo synthesized fatty acids in the formation of rumen microbial lipids in vitro. Applied and Environmental Microbiology 35, 24–30.CrossRefGoogle ScholarPubMed
Demeyer, DI & Hoozee, J (1984) Schatting van linolzuursynthese in de pens van een schaap bij eiwit- en vetvrije voedering (Estimation of linoleic acid synthesis in the rumen of a sheep fed a protein and fat free diet). Proceedings van de 9de Studiedag voor Nederlandstalige Voedingsonderzoekers (Proceedings of 9th Meeting of Dutch Speaking Nutritionists), Utrecht, pp. 27–29. Vakgroep ZoötechniekUniversity of Utrecht.Google Scholar
DePeters, EJ, Medrano, JF & Reed, BA (1995) Fatty acid composition of milk fat from three breeds of dairy cattle. Canadian Journal of Animal Science 75, 267–269.CrossRefGoogle Scholar
Dhiman, TR, Helmink, ED, McMahon, DJ, Fife, RL & Pariza, MW;(1998) Conjugated linoleic acid content of milk from cows fed extruded oilseeds. Journal of Dairy Science 81, Suppl. 1, 353.Google Scholar
Dhiman, TR, Satter, LD, Pariza, MW, Galli, MP & Albright, K (1997) Conjugated linoleic acid (CLA) content of milk from cows offered diets rich in linoleic and linolenic acid. Journal of Dairy Science 80, Suppl. 1, 184.Google Scholar
Dong, Y, Bae, HD, McAllister, TA, Mathiso, GW & Cheng, KJ (1997) Lipid-induced depression of methane production and digestibility in the artificial rumen system. Canadian Journal of Animal Science 77, 269–278.Google Scholar
Doreau, M & Chilliard, Y (1997 a) Effects of ruminal or postruminal fish oil supplementation on intake and digestion in dairy cows. Reproduction Nutrition Développement 37, 113–124.CrossRefGoogle ScholarPubMed
Doreau, M & Chilliard, Y (1997 b) Digestion and metabolism of dietary fat in farm animals. British Journal of Nutrition 78, Suppl. 1, S15–S35.Google Scholar
Doreau, M, Demeyer, DI & Van Nevel, CJ (1997) Transformation and effects of unsaturated fatty acids in the rumen. Consequences on milk fat secretion. In Milk Composition, Production and Biotechnology, pp. 73–92 [Welch, RAS, Burns, DJW, Davis, SR, Popay, AI and Prosser, CG, editors]. New York: CAB International.Google Scholar
EEC (1981) Council Regulation (EEC) no. 1208/81 of 28 April 1981 Determining the Community Scale for the Classification of Carcases of Adult Bovine Animals. Strasbourg: EEC.Google Scholar
EEC (1991) Council Regulation (EEC) no. 1026/91 of 22 April 1991 Amending Regulation (EEC) no. 1208/81 Determining the Community Scale for the Classification of Carcases of Adult Bovine Animals. Strasbourg: EEC.Google Scholar
Enjalbert, F, Nicot, MC, Vernay, M, Moncoulon, R & Griess, D (1994) Effect of different forms of polyunsaturated fatty acids on duodenal and serum fatty acid profiles in sheep. Canadian Journal of Animal Science 74, 595–600.CrossRefGoogle Scholar
Enser, M, Hallet, KG, Hewett, B, Fursey, GAJ, Wood, JD & Harrington, G (1998) Fatty acid content and composition of UK beef and lamb muscle in relation to production system and implications for human nutrition. Meat Science 49, 329–341.CrossRefGoogle ScholarPubMed
Erdman, RA, Teter, BT, Keeney, M & Sampugna, J (1995) Method for regulating milk fat and milk production using trans-fatty acids. United States Patent 5, 416, 115.Google Scholar
Fellner, V, Sauer, FD & Kramer, JKG (1995) Steady-state rates of linoleic acid biohydrogenation by ruminal bacteria in continuous culture. Journal of Dairy Science 78, 1815–1823.Google Scholar
Fellner, V, Sauer, FD & Kramer, JKG (1997) Effect of nigericin, monensin, and tetronasin on biohydrogenation in continuous flow-through ruminal fermenters. Journal of Dairy Science 80, 921–928.CrossRefGoogle ScholarPubMed
Ferlay, A, Chilliard, Y & Doreau, M (1992) Effects of calcium salts differing in fatty acid composition on duodenal and milk fatty acid profiles in dairy cows. Journal of the Science of Food and Agriculture 60, 31–37.CrossRefGoogle Scholar
Fiems, LO, Buts, B, Boucqué Ch, V, Demeyer, DI & Cottyn, BJ (1990) Effect of a β--agonist on meat quality and myofibrillar protein fragmentation in bulls. Meat Science 27, 29–39.Google Scholar
Fiems, LO, de Campeneere, S, Bogaerts, DF, Cottyn, BG & Boucqué Ch, V (1998) The influence of dietary energy and protein levels on performance, carcass and meat quality of Belgian White-blue double-muscled finishing bulls. Animal Science 66, 319–327.CrossRefGoogle Scholar
Flachowski, G & Jahreis, G (1997) Fettsäurenaufnahme des Menschen und Möglichkeiten der Beeinflussung durch die Tierenährung (Fatty acid intake in man and possibilities of influence by animal foods). Fett/Lipid 99, 106–115.Google Scholar
Flint, DJ, Cryer, A, Kestin, S, Griffin, H, Butterwith, S, Rhind, S, Futter, C, Tonner, E, Kennedy, R, Cryer, J & Marsh, J (1994) Manipulation of body fat using antibodies raised against plasma membrane antigens of adipocytes. In Vaccines in Agriculture, pp. 129–135 [Wood, PR, Willadse, P, Vercoe, JE, Hoskinson, RM and Demeyer, D, editors]. Melbourne: CSIRO Information Services.Google Scholar
Fredeen, AH (1996) Considerations in the nutritional modification of milk composition. Animal Feed Science and Technology 59, 185–197.CrossRefGoogle Scholar
Gandemer, G (1997) Lipides du muscle et qualité de la viande. Phospholipides et flaveur (Muscle lipid and meat quality. Phospholipids and flavour). Oléagineux-Corps gras-Lipides 4, 19–25.Google Scholar
Gaynor, PJ, Erdman, RA, Teter, BB, Capuco, AV & Waldo, DR (1996) Glucose and norepinephrine challenges during abomasal infusion of cis or trans octadecenoates in Holstein cows. Journal of Dairy Science 79, 1590–1596.Google Scholar
Gaynor, PJ, Erdman, RA, Teter, BB, Sampugna, J, Capuco, AV, Waldo, DR & Hamosh, M (1994) Milk fat yield and composition during abomasal infusion of cis or trans octadecanoates in Holstein cows. Journal of Dairy Science 77, 157–165.CrossRefGoogle ScholarPubMed
Gerson, T, John, A & King, ASD (1985) The effects of dietary starch and fibre on the in vitro rates of lipolysis and hydrogenation by sheep rumen digesta. Journal of Agricultural Science, Cambridge 105, 97–101.CrossRefGoogle Scholar
Gormley, TR, Downey, G & O’Beirne, D (1987) Food, Health and the Consumer. London: Elsevier Applied Sciences.Google Scholar
Griinari, JM, Chouinard, PY & Bauman, DE (1997) Trans fatty acid hypothesis of milk fat depression revised. In Proceedings of the Cornell Nutrition Conference for Feed Manufacturers, pp. 208–216. Ithaca, NY: Cornell University Press.Google Scholar
Griinari, JM, Nurmela, K, Sairanen, A, Nousiainen, JI & Khalili, H (1998) Effect of dietary sunflower oil and pasture forage maturity on conjugated linoleic acid (CLA) content in milk fat from lactating dairy cows. Journal of Dairy Science 81, Suppl. 1, 300.Google Scholar
Grummer, RR (1988) Influence of prilled fat and calcium salts of palm oil fatty acids on ruminal fermentation. Journal of Dairy Science 71, 117–123.CrossRefGoogle Scholar
Gulati, SK, Scott, TW & Ashes, JR (1997) In-vitro assessment of fat supplements for ruminants. Animal Feed Science and Technology 64, 127–132.Google Scholar
Gurr, MI & James, AT (editors) (1980) The biochemistry of fatty acids. In Lipid Biochemistry, pp. 25–87. New York: Chapman & Hall.Google Scholar
Hagemeister, H, Precht, D & Barth, CA (1988) Studies on the transfer of omega-3 fatty acids into bovine milk fat. Milchwissenschaft 43, 153–158.Google Scholar
Hansen, HO & Knudsen, J (1987) Effect of exogenous long-chain fatty acids on lipid biosynthesis in dispersed ruminant mammary gland epithelial cells: esterification of long-chain exogenous fatty acids. Journal of Dairy Science 70, 1344–1349.CrossRefGoogle ScholarPubMed
Harfoot, CG & Hazlewood, GP (1997) Lipid metabolism in the rumen. In The Rumen Microbial Ecosystem, pp. 382–426 [Hobson, PN and Stewart, CS, editors]. Glasgow: Blackie Academic & Professional.CrossRefGoogle Scholar
Hornick, JL, van Eenaeme, C, Clinquart, A, Diez, M & Istasse, L (1998) Different periods of feed restriction before compensatory growth in Belgian Blue bulls: I. Animal performance, nitrogen balance, meat characteristics, and fat composition. Journal of Animal Science 76, 249–259.CrossRefGoogle ScholarPubMed
Huerta-Leidenz, NO, Cross, HR, Savell, JW, Lunt, DK, Naker, JF, Pelton, LS & Smith, SB (1993) Comparison of the fatty acid composition of subcutaneous adipose tissue from mature Brahman and Hereford cows. Journal of Animal Science 71, 625–630.CrossRefGoogle ScholarPubMed
Hussein, HS, Merchen, NR & Fahey, GC (1995) Composition of ruminal bacteria harvested from steers as influenced by dietary forage level and fat supplementation. Journal of Animal Science 73, 2469–2473.Google Scholar
Huyghebaert, A, Verhaeghe, D & De Moor, H (1994) Fat products using chemical and enzymatic interesterification. In Fats in Food Products, pp. 319–345 [Moran, DPJ and Rajah, KK, editors]. Glasgow: Blackie Academic and Professional.Google Scholar
Immig, I, Van Nevel, C & Demeyer, DI (1993) Lipolysis and hydrogenation of soyabean oil in the rumen of sheep. In Proceedings of the Society of Nutrition Physiology, vol. 1, p. 59[Giesecke, D, editor]. Frankfurt: DLG–Verlag.Google Scholar
Ip, C & Marshall, JR (1996) Trans fatty acids and cancer. Nutrition Reviews 54, 138–145.Google Scholar
Jenkins, TC (1994) Regulation of lipid metabolism in the rumen. Journal of Nutrition 124, 1372S–1376S.Google Scholar
Jenkins, TC, Bateman, HG & Block, SM (1996) Butylsoyamide increases unsaturation of fatty acids in plasma and milk of lactating dairy cows. Journal of Dairy Science 79, 585–590.CrossRefGoogle ScholarPubMed
Jiang, J, Bjoerck, L, Fondén, R & Emanuelson, M (1996) Occurrence of conjugated cis-9, trans-11-octadecadienoic acid in bovine milk: effects of feed and dietary regimen. Journal of Dairy Science 79, 438–445.CrossRefGoogle ScholarPubMed
Jump, DB, Clarke, SD, Thelen, A, Liimatta, M, Ren, B & Badin, M (1996) Dietary polyunsaturated fatty acid regulation of gene transcription. Progress in Lipid Research 35, 227–241.CrossRefGoogle ScholarPubMed
Kalscheur, KF, Teter, BB, Piperova, LS & Erdman, RA (1997) Effect of fat source on duodenal flow of trans-C18 : 1 fatty acids and milk fat production in dairy cows. Journal of Dairy Science 80, 2115–2126.Google Scholar
Kelly, ML & Bauman, DE (1996) Conjugated linoleic acid: a potent anticarcinogen found in milk fat. In Proceedings of the Cornell Nutrition Conference for Feed Manufacturers, pp. 68–74. Ithaca, NY: Cornell University Press.Google Scholar
Kelly, ML, Berry, JR, Dwyer, DA, Bauman, DE, Van Amburgh, ME & Griinari, JM (1997) Effect of dietary fatty acid sources on conjugated linoleic acid (CLA) levels in milk from lactating dairy cows. Journal of Dairy Science 80, Suppl. 1, 243.Google Scholar
Kennelly, JJ (1996 a) Producing milk with 2.5 % fat - the biology and health implications for dairy cows. Animal Feed Science and Technology 60, 161–180.CrossRefGoogle Scholar
Kennelly, JJ (1996 b) The fatty acid composition of milk fat as influenced by feeding oilseeds. Animal Feed Science and Technology 60, 137–152.Google Scholar
Kinsella, JE, Lokesh, B & Stone, RA (1990) Dietary n−3 polyunsaturated fatty acids and amelioration of cardiovascular disease: possible mechanisms. American Journal of Clinical Nutrition 52, 1–28.Google Scholar
Kobayashi, Y, Wakita, M & Hoshino, S (1992) Effects of the ionophore salinomycin on nitrogen and long-chain fatty acids profiles of digesta in the rumen and duodenum of sheep. Animal Feed Science and Technology 36, 67–76.Google Scholar
Larick, DK & Turner, BE (1989) Influence of finishing diet on the phospholipid composition and fatty acid profile of individual phospholipids in lean muscle of beef cattle. Journal of Animal Science 67, 2282–2293.Google Scholar
Lawrence, TLJ & Fowler, VR (1997) Growth of Farm Animals. New York: CAB International.Google Scholar
Lin, H, Boylston, D, Chang, MJ, Luedecke, LO & Shultz, TD (1995) Survey of the conjugated linoleic acid contents of dairy products. Journal of Dairy Science 78, 2358–2365.CrossRefGoogle ScholarPubMed
McDonald, IW & Scott, TW (1977) Foods of ruminant origin with elevated content of polyunsaturated fatty acids. World Review of Nutrition and Dietetics 26, 144–207.CrossRefGoogle Scholar
McFadden, T & Trumble, W (1997) OECD Project Report. Paris: OECD.Google Scholar
McGuire, MA, McGuire, MK, McGuire, MS & Griinari, JM (1997) Bovinic acid: the natural CLA. In Proceedings of the Cornell Nutrition Conference for Feed Manufacturers, pp. 217–226. Ithaca, NY: Cornell University Press.Google Scholar
Mansbridge, RJ & Blake, JS (1997) Nutritional factors affecting the fatty acid composition of bovine milk. British Journal of Nutrition 78, Suppl. 1, S37–S47.Google Scholar
Mersmann, HJ (1990) Metabolic and endocrine control of adipose tissue accretion. In Reducing Fat in Meat Animals, pp. 101–144 [Wood, JD and Fisher, AV, editors]. London: Elsevier Applied Science.Google Scholar
Miles, EA & Calder, PC (1998) Modulation of immune function by dietary fatty acids. Proceedings of the Nutrition Society 57, 277–299.Google Scholar
Minet, V, Van Eenaeme, C, Raskin, P, Dufrasne, I, Clinquart, A, Hornick, JL, Diez, M, Mayombo, P, Baldwin, P, Bienfait, J-M & Istasse, L (1996) Stratègies d’Engraissement du Taurillon Blanc Bleu Belge Culard (Fattening Strategies for Double Muscled Belgian Blue White Bulls). Brussels: Ministerie van Middenstand en Landbouw.Google Scholar
Murphy, JJ, Connolly, JF & McNeill, GP (1995) Effects on cow performance and milk fat composition of feeding full fat soya beans and rapeseeds to dairy cows at pasture. Livestock Production Science 44, 13–25.CrossRefGoogle Scholar
Murphy, JJ & O’Mara, F (1993) Nutritional manipulation of milk protein concentration and its impact on the dairy industry. Livestock Production Science 35, 117–134.Google Scholar
Nicolisi, RJ (1997) Dietary fat saturation effects on low-density-lipoprotein concentrations and metabolism in various animal models. American Journal of Clinical Nutrition 65, 1617S–1627S.CrossRefGoogle Scholar
Noble, RC, Moore, JH & Harfoot, CG (1974) Observations on the pattern of biohydrogenation of esterified and unesterified linoleic acid in the rumen. British Journal of Nutrition 31, 99–108.CrossRefGoogle ScholarPubMed
O’Kelly, JC & Spiers, WG (1991) Influence of host diet on the concentrations of fatty acids in rumen bacteria from cattle. Australian Journal of Agricultural Research 42, 243–252.CrossRefGoogle Scholar
Palmquist, DL & Moser, E (1981) Dietary fat effects on blood insulin, glucose utilization and milk protein content of lactating cows. Journal of Dairy Science 64, 1664–1670.CrossRefGoogle ScholarPubMed
Precht, D & Molkentin, J (1995) Trans fatty acids: implications for health, analytical methods, incidence in edible fats and intake. Die Nahrung 39, 343–374.Google Scholar
Precht, D & Molkentin, J (1997) Vergleich der Fettsäuren und der Isomerenverteilung der trans-C18 : 1-Fettsäuren von Milchfett, Margarine, Back-, Brat- und Diatfetten (Comparison of the fatty acids and the isomer distribution of trans-C18 : 1 fatty acids in milk fat, margarine, baking, grilling and diet fats). Kieler Milchwirtschaftliche Forschungsberichte 49, 17–34.Google Scholar
Reddy, PV, Morrill, JL & Nagaraja, TG (1994) Release of free fatty acids from raw or processed soybeans and subsequent effects on fiber digestibilities. Journal of Dairy Science 77, 3410–3416.Google Scholar
Sinclair, AJ & O’Dea, K (1990) Fats in human diets through history: is the Western diet out of step. In Reducing Fat in Meat Animals, pp. 1–47 [Wood, JD and Fisher, AV, editors]. London: Elsevier Applied Science.Google Scholar
Truswell, AS (1995) Dietary Fat: Some Aspects of Nutrition and Health and Product Development. ILSI Europe Concise Monograph Series. Brussels: ILSI Press.Google Scholar
Urbach, G (1990) Effect of feed on flavor in dairy foods. Journal of Dairy Science 73, 3639–3650.Google Scholar
Van Amburgh, ME (1997) Effect of ionophores on growth and lactation in cattle. In Proceedings of the Cornell Nutrition Conference for Feed Manufacturers, pp. 93–103. Ithaca, NY: Cornell University Press.Google Scholar
Van Dokkum, W (1995) Novel foods. De Waren-Chemicus 25, 98–104.Google Scholar
Van Eenaeme, C, Clinquart, A, Baldwin, P, Mayombo, P, Istasse, L & Bienfait, J-M (1991) Metabolic and hormonal effects of a fat concentrate in the diet of growing and fattening bulls of different breeds. Mededelingen Faculteit Landbouwwetenschappen Rijksuniversiteit Gent 56, 1601–1610.Google Scholar
Van Nevel, C & Demeyer, D (1996 a) Lipolysis and biohydrogenation of soyabean oil in the rumen in vitro: inhibition by antimicrobials. Journal of Dairy Science 78, 2797–2806.Google Scholar
Van Nevel, CJ & Demeyer, D (1996 b) Effect of pH on biohydrogenation of polyunsaturated fatty acids and their Ca-salts by rumen micro-organisms in vitro. Archives of Animal Nutrition 49, 151–157.Google Scholar
Van Nevel, CJ & Demeyer, DI (1996 c) Influence of pH on lipolysis and biohydrogenation of soyabean oil by rumen contents in vitro. Reproduction Nutrition Développement 36, 53–63.Google Scholar
Van Nevel, C, Fievez, V & Demeyer, D (1999) Lipolysis and biohydrogenation of PUFAs from fish oil during in vitro incubations with rumen contents. Proceedings of the Nutrition Society (In the Press).Google Scholar
Vatansever, L, Kurt, E, Enser, M, Scollan, ND, Richardson, RI, Nute, GR & Wood, JD (1998) The quality of beef from steers fed supplements of n−3 polyunsaturated fatty acids. In Proceedings 44th International Congress of Meat Science and Technology, Barcelona, Spain, pp. 656–657 [Diestre, A and Monfort, JM, editors]. Barcelona: IRTA.Google Scholar
Vernon, RG & Flint, DF (1988) Lipid metabolism in farm animals. Proceedings of the Nutrition Society 47, 287–293.Google Scholar
Webb, EC, De Smet, S, Van Nevel, C, Martens, B & Demeyer, DI (1998) Effect of anatomical location on the composition of fatty acids in double-muscled Belgian Blue cows. Meat Science 50, 45–53.Google Scholar
Weisbjerg, MR, Børsting, CF & Hvelplund, T (1992) The influence of tallow on rumen metabolism, microbial biomass synthesis and fatty acid composition of bacteria and protozoa. Acta Agricultura Scandinavica 42A, 138–147.Google Scholar
Willett, WC, Stampfer, MJ, Manson, JE, Colditz, GA, Speizer, FE, Rosner, BA, Sampson, LA & Hennekens, CH (1993) Intake of trans fatty acids and risk of coronary heart disease among women. Lancet 341, 581–585.CrossRefGoogle ScholarPubMed
Wolff, RL (1995) Content and distribution of trans−18 : 1 acids in ruminant milk and meat fats. Their importance in European diets and their effect on human milk. Journal of the American Oil Chemists Society 72, 259–272.Google Scholar
Wood, JD (1984) Fat deposition and the quality of fat tissue in meat animals. In Fats in Animal Nutrition, pp. 407–435[Wiseman, RJ, editor]. London: Butterworths.CrossRefGoogle Scholar
Wood, JD (1990) Consequences for meat quality of reducing carcass fatness. In Reducing Fat in Meat Animals, pp. 344–397 [Wood, JD and Fisher, AV, editors]. London: Elsevier Applied Science.Google Scholar
Wood, JD & Enser, M (1997) Factors influencing fatty acids in meat and the role of antioxidants in improving meat quality. British Journal of Nutrition 78, Suppl. 1, S49–S60.Google Scholar
Wu, Z, Ohajuruka, OA & Palmquist, DL (1991) Ruminal synthesis, biohydrogenation and digestibility of fatty acids by dairy cows. Journal of Dairy Science 74, 3025–3034.Google Scholar
Zock, PL & Katan, MB (1997) Trans fatty acids, lipoproteins, and coronary risk. Canadian Journal of Physiology and Pharmacology 75, 211–216.Google Scholar