Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-15T07:35:37.675Z Has data issue: false hasContentIssue false
  • English
  • Français

The role of microbes in rumen lipolysis and biohydrogenation and their manipulation

Published online by Cambridge University Press:  23 March 2010

M. Lourenço ,
E. Ramos-Morales  and
R. J. Wallace
M. Lourenço
Affiliation:
Department of Animal Production, Ghent University, Laboratory for Animal Nutrition and Animal Product Quality, Proefhoevestraat 10, 9090 Melle, Belgium
E. Ramos-Morales
Affiliation:
Gut Health Division, University of Aberdeen, Rowett Institute of Nutrition and Health, Greenburn Road, Bucksburn, UK
R. J. Wallace*
Affiliation:
Gut Health Division, University of Aberdeen, Rowett Institute of Nutrition and Health, Greenburn Road, Bucksburn, UK
*
†E-mail: john.wallace@abdn.ac.uk
Get access

Abstract

Despite the fact that the ruminant diet is rich in polyunsaturated fatty acids (PUFA), ruminant products – meat, milk and dairy – contain mainly saturated fatty acids (SFA) because of bacterial lipolysis and subsequent biohydrogenation of ingested PUFA in the rumen. The link between SFA consumption by man and coronary heart disease is well established. In contrast, ruminant products also contain fatty acids that are known to be beneficial to human health, namely conjugated linoleic acids (CLAs). The aims of research in this field have been to understand the microbial ecology of lipolysis and biohydrogenation and to find ways of manipulating ruminal microbes to increase the flow of PUFA and CLA from the rumen into meat and milk. This review describes our present understanding of the microbial ecology of ruminal lipid metabolism, including some apparently anomalous and paradoxical observations, and the status of how the metabolism may be manipulated and the possible consequential effects on other aspects of ruminal digestion. Intuitively, it may appear that inhibiting the ruminal lipase would cause more dietary PUFA to reach the mammary gland. However, lipolysis releases the non-esterified fatty acids that form the substrates for biohydrogenation, but which can, if they accumulate, inhibit the whole process. Thus, increasing lipase activity could be beneficial if the increased release of non-esterified PUFA inhibited the metabolism of CLA. Rumen ciliate protozoa do not carry out biohydrogenation, yet protozoal lipids are much more highly enriched in CLA than bacterial lipids. How could this happen if protozoa do not metabolise PUFA? The answer seems to lie in the ingestion of plant organelles, particularly chloroplasts, and the partial metabolism of the fatty acids by contaminating bacteria. Bacteria related to Butyrivibrio fibrisolvens are by far the most active and numerous biohydrogenating bacteria isolated from the rumen. But do we misunderstand the role of different bacterial species in biohydrogenation because there are uncultivated species that we need to understand and include in the analysis? Manipulation methods include dietary vegetable and fish oils and plant-derived chemicals. Their usefulness, efficacy and possible effects on fatty acid metabolism and on ruminal microorganisms and other areas of their metabolism are described, and areas of opportunity identified.

Keywords

biohydrogenationcellulose digestionlipasemicrobial protein synthesisrumen
Type
Full Paper
Information
animal , Volume 4 , Issue 7: XIth International Symposium on Ruminant Physiology (ISRP), 6–9 September, 2009 Clermont-Ferrand (France) , July 2010 , pp. 1008 - 1023
Copyright
Copyright © The Animal Consortium 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abaza, MA, Abouakkada, AR, Elshazly, K 1975. Effect of rumen protozoa on dietary lipid in sheep. The Journal of Agricultural Science 85, 135–143.CrossRefGoogle Scholar
Abe, M, Iriki, T, Tobe, N, Shibui, H 1981. Sequestration of holotrich protozoa in the reticulo-rumen of cattle. Applied and Environmental Microbiology 41, 758–765.CrossRefGoogle ScholarPubMed
AbuGhazaleh, AA, Jenkins, TC 2004. Short communication: docosahexaenoic acid promotes vaccenic acid accumulation in mixed ruminal cultures when incubated with linoleic acid. Journal of Dairy Science 87, 1047–1050.CrossRefGoogle ScholarPubMed
Amorocho, AK, Jenkins, TC, Staples, CR 2009. Evaluation of catfish oil as a feedstuff for lactating Holstein cows. Journal of Dairy Science 92, 5178–5188.CrossRefGoogle ScholarPubMed
Ankrah, P, Loerch, SC, Kampman, KA, Dehority, BA 1990. Effects of defaunation on in situ dry matter and nitrogen disappearance in steers and growth of lambs. Journal of Animal Science 68, 3330–3336.CrossRefGoogle ScholarPubMed
Arpigny, JL, Jaeger, KE 1999. Bacterial lipolytic enzymes: classification and properties. The Biochemical Journal 343, 177–183.CrossRefGoogle ScholarPubMed
Bailey, RW, Howard, BH 1963. Carbohydrates of the rumen ciliate Epidinium caudatum (Crawley). 2. α-Galactosidase and isomaltase. Biochemical Journal 87, 146–151.CrossRefGoogle Scholar
Bauman, DE, Griinari, JM 2001. Regulation and nutritional manipulation of milk fat: low-fat milk syndrome. Livestock Production Science 70, 15–29.CrossRefGoogle Scholar
Baumgard, LH, Corl, BA, Dwyer, DA, Saebø, A, Bauman, DE 2000. Identification of the conjugated linoleic acid isomer that inhibits milk fat synthesis. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology 278, R179–R184.CrossRefGoogle ScholarPubMed
Benchaar, C, Petit, HV, Berthiaume, R, Whyte, TD, Chouinard, PY 2006. Effects of addition of essential oils and monensin premix on digestion, ruminal fermentation, milk production, and milk composition in dairy cows. Journal of Dairy Science 89, 4352–4364.CrossRefGoogle ScholarPubMed
Benchaar, C, Petit, HV, Berthiaume, R, Ouellet, DR, Chiquette, J, Chouinard, PY 2007. Effects of essential oils on digestion, ruminal fermentation, rumen microbial populations, milk production, and milk composition in dairy cows fed alfalfa silage or corn silage. Journal of Dairy Science 90, 886–897.CrossRefGoogle ScholarPubMed
Benchaar, C, Calsamiglia, S, Chaves, AV, Fraser, GR, Colombatto, D, McAllister, TA, Beauchemin, KA 2008. A review of plant-derived essential oils in ruminant nutrition and production. Animal Feed Science and Technology 145, 209–228.CrossRefGoogle Scholar
Bergen, WG, Bates, DB 1984. Ionophores – their effect on production efficiency and mode of action. Journal of Animal Science 58, 1465–1483.CrossRefGoogle ScholarPubMed
Bhatta, R, Krishnamoorthy, U, Mohammed, F 2000. Effect of feeding tamarind (Tamarindus indica) seed husk as a source of tannin on dry matter intake, digestibility of nutrients and production performance of crossbred dairy cows in mid-lactation. Animal Feed Science and Technology 83, 67–74.CrossRefGoogle Scholar
Boeckaert, C, Vlaeminck, B, Mestdagh, J, Fievez, V 2007a. In vitro examination of DHA-edible micro algae 1. Effect on rumen lipolysis and biohydrogenation of linoleic and linolenic acids. Animal Feed Science and Technology 136, 63–79.CrossRefGoogle Scholar
Boeckaert, C, Fievez, V, Van Hecke, D, Verstraete, W, Boon, N 2007b. Changes in rumen biohydrogenation intermediates and ciliate protozoa diversity after algae supplementation to dairy cattle. European Journal of Lipid Science and Technology 109, 767–777.CrossRefGoogle Scholar
Boeckaert, C, Vlaeminck, B, Fievez, V, Maignien, L, Dijkstra, J, Boon, N 2008. Accumulation of trans C-18:1 fatty acids in the rumen after dietary algal supplementation is associated with changes in the Butyrivibrio community. Applied and Environmental Microbiology 74, 6923–6930.CrossRefGoogle ScholarPubMed
Boeckaert, C, Morgavi, DP, Jouany, JP, Maignien, L, Boon, N, Fievez, V 2009. Role of the protozoan Isotricha prostoma, liquid-, and solid-associated bacteria in rumen biohydrogenation of linoleic acid. Animal 3, 961–971.CrossRefGoogle ScholarPubMed
Broudiscou, LP, Cornu, A, Rouzeau, A 2007. In vitro degradation of 10 mono- and sesquiterpenes of plant origin by caprine rumen micro-organisms. Journal of the Science of Food and Agriculture 87, 1653–1658.CrossRefGoogle Scholar
Bu, DP, Wang, JQ, Dhiman, TR, Liu, SJ 2007. Effectiveness of oils rich in linoleic and linolenic acids to enhance conjugated linoleic acid in milk from dairy cows. Journal of Dairy Science 90, 998–1007.CrossRefGoogle Scholar
Cabiddu, A, Addis, M, Pinna, G, Spada, S, Fiori, M, Sitzia, M, Pirisi, A, Piredda, G, Molle, G 2006. The inclusion of a daisy plant (Chrysanthemum coronarium) in dairy sheep diet. 1: effect on milk and cheese fatty acid composition with particular reference to C18:2 cis-9, trans-11. Livestock Science 101, 57–67.CrossRefGoogle Scholar
Calsamiglia, S, Busquet, M, Cardozo, PW, Castillejos, L, Ferret, A 2007. Invited review: essential oils as modifiers of rumen microbial fermentation. Journal of Dairy Science 90, 2580–2595.CrossRefGoogle ScholarPubMed
Castillejos, L, Calsamiglia, S, Ferret, A, Losa, R 2005. Effects of a specific blend of essential oil compounds and the type of diet on rumen microbial fermentation and nutrient flow from a continuous culture system. Animal Feed Science and Technology 119, 29–41.CrossRefGoogle Scholar
Castillejos, L, Calsamiglia, S, Ferret, A 2006. Effect of essential oil active compounds on rumen microbial fermentation and nutrient flow in in vitro systems. Journal of Dairy Science 89, 2649–2658.CrossRefGoogle ScholarPubMed
Castillejos, L, Calsamiglia, S, Ferret, A, Losa, R 2007. Effects of dose and adaptation time of a specific blend of essential oil compounds on rumen fermentation. Animal Feed Science and Technology 132, 186–201.CrossRefGoogle Scholar
Castillejos, L, Calsamiglia, S, Martín-Tereso, J, Ter Wijlen, H 2008. In vitro evaluation of effects of ten essential oils at three doses on ruminal fermentation of high concentrate feedlot-type diets. Animal Feed Science and Technology 145, 259–270.CrossRefGoogle Scholar
Chen, M, Wolin, MJ 1979. Effect of monensin and lasocid sodium on the growth of methanogenic and rumen saccharolytic bacteria. Applied and Environmental Microbiology 38, 72–77.CrossRefGoogle ScholarPubMed
Chesson, A, Forsberg, CW 1997. Polysaccharide degradation by rumen microorganisms. In The rumen microbial ecosystem (ed. PN Hobson and CS Stewart), pp. 329–381. Chapman & Hall, London, UK.CrossRefGoogle Scholar
Chilliard, Y, Glasser, F, Ferlay, A, Bernard, L, Rouel, J, Doreau, M 2007. Diet, rumen biohydrogenation and nutritional quality of cow and goat milk fat. European Journal of Lipid Science and Technology 109, 828–855.CrossRefGoogle Scholar
Chin, SF, Liu, W, Albright, K, Pariza, MW 1992. Tissue levels of cis-9, trans-11 conjugated dienoic isomer of linoleic acid (CLA) in rats fed linoleic acid (LA). The FASEB Journal 6, A1396.Google Scholar
Coleman, GS, Kemp, P, Dawson, RMC 1971. The catabolism of phosphatidylethanolamine by the rumen protozoon Entodinium caudatum and its conversion to the N-(1-carboxyethyl) derivative. The Biochemical Journal 123, 97–104.CrossRefGoogle Scholar
Crozier, A, Jaganath, IB, Clifford, MN 2006. Phenols, polyphenols and tannins: an overview. In Plant secondary metabolites – occurrence, structure and role in the human diet (ed. A Crozier, MN Clifford and H Ashihara), pp. 1–24. Blackwell Publishsing, Iowa, USA.CrossRefGoogle Scholar
Daniel, ZC, Wynn, RJ, Salter, AM, Buttery, PJ 2004. Differing effects of forage and concentrate diets on the oleic acid and conjugated linoleic acid content of sheep tissues: the role of stearoyl-CoA desaturase. Journal of Animal Science 82, 747–758.CrossRefGoogle ScholarPubMed
Da Silva, DC, Santos, GT, Branco, AF, Damasceno, JC, Kazama, R, Matsushita, M, Horst, JA, dos Santos, WBR, Petit, HV 2007. Production performance and milk composition of dairy cows fed whole or ground flaxseed with or without monensin. Journal of Dairy Science 90, 2928–2936.CrossRefGoogle ScholarPubMed
Dawson, RMC, Hemington, N 1974. Digestion of grass lipids and pigments in the sheep rumen. The British Journal of Nutrition 32, 327–340.CrossRefGoogle ScholarPubMed
Dawson, RMC, Kemp, P 1969. The effect of defaunation on the phospholipids and on the hydrogenation of unsaturated fatty acids in the rumen. The Biochemical Journal 115, 351–352.CrossRefGoogle ScholarPubMed
Dawson, RMC, Hemington, N, Hazlewood, GD 1977. On the role of higher plant and microbial lipases in the ruminal hydrolysis of grass lipids. The British Journal of Nutrition 38, 225–232.CrossRefGoogle ScholarPubMed
Devillard, E, Wallace, RJ 2006. Biohydrogenation in the rumen and human intestine: implications for CLA and PUFA. Lipid Technology 18,, 127–130.Google Scholar
Devillard, E, McIntosh, FM, Newbold, CJ, Wallace, RJ 2006. Rumen ciliate protozoa contain high concentrations of conjugated linoleic acids and VA, yet do not hydrogenate linoleic acid or desaturate stearic acid. The British Journal of Nutrition 96, 697–704.Google ScholarPubMed
Dewhurst, RJ, Shingfield, KJ, Lee, MRF, Scollan, ND 2006. Increasing the concentrations of beneficial polyunsaturated fatty acids in milk produced by dairy cows in high-forage systems. Animal Feed Science and Technology 131, 168–206.CrossRefGoogle Scholar
Dhiman, TR, Satter, LD, Pariza, MW, Galli, MP, Albright, K, Tolosa, MX 2000. Conjugated linoleic acid (CLA) content of milk from cows offered diets rich in linoleic and linolenic acid. Journal of Dairy Science 83, 1016–1027.CrossRefGoogle Scholar
Dong, Y, Bae, HD, McAllister, TA, Mathison, GW, Cheng, KJ 1997. Lipid-induced depression of methane production and digestibility in the artificial rumen system (RUSITEC). Canadian Journal of Animal Science 77, 269–278.CrossRefGoogle Scholar
Durmic, Z, McSweeny, CS, Kemp, GW, Hutton, P, Wallace, RJ, Vercoe, PE 2008. Australian plants with potential to inhibit bacteria and processes involved in ruminal biohydrogenation of fatty acids. Animal Feed Science and Technology 145, 271–284.CrossRefGoogle Scholar
Elgersma, A, Tamminga, S, Ellen, G 2006. Modifying milk composition through forage. Animal Feed Science and Technology 131, 207–225.CrossRefGoogle 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
Fievez, V, Dohme, F, Danneels, M, Raes, K, Demeyer, D 2003. Fish oils as potent rumen methane inhibitors and associated effects on rumen fermentation in vitro and in vivo. Animal Feed Science and Technology 104, 41–58.CrossRefGoogle Scholar
Fievez, V, Vlaeminck, B, Jenkins, T, Enjalbert, F, Doreau, M 2007. Assessing rumen biohydrogenation and its manipulation in vivo, in vitro and in situ. European Journal of Lipid Science and Technology 109, 740–756.CrossRefGoogle Scholar
Franklin, ST, Martin, KR, Baer, RJ, Schingoethe, DJ, Hippen, AR 1999. Dietary marine algae (Schizochytrium sp) increases concentrations of conjugated linoleic, docosahexaenoic and transvaccenic acids in milk of dairy cows. The Journal of Nutrition 129, 2048–2054.CrossRefGoogle ScholarPubMed
French, P, Stanton, C, Lawless, F, O’Riordan, EG, Monahan, FJ, Caffrey, PJ, Moloney, AP 2000. Fatty acid composition, including conjugated linoleic acid of intramuscular fat from steers offered grazed grass, grass silage or concentrate-based diets. Journal of Animal Science 78, 2849–2855.CrossRefGoogle ScholarPubMed
Garton, GA 1977. Fatty acid metabolism in ruminants. In International review of biochemistry of lipids II (ed. TW Goodwin), vol. 14, pp. 337–370. University Park Press, Baltimore, USA.Google Scholar
Garton, GA, Hobson, PN, Lough, AK 1958. Lipolysis in the rumen. Nature 182, 1511–1512.CrossRefGoogle ScholarPubMed
Girard, V, Hawke, JC 1978. The role of holotrichs in the metabolism of dietary linoleic acid in the rumen. Biochimica et Biophysica Acta 528, 17–27.CrossRefGoogle Scholar
Givens, DI 2005. The role of animal nutrition in improving the nutritive value of animal-derived foods in relation to chronic disease. The Proceedings of the Nutrition Society 64, 395–402.CrossRefGoogle ScholarPubMed
Givens, DI, Shingfield, KJ 2004. Food derived from animals: the impact of animal nutrition on their nutritive value and ability to sustain long-term health. Nutrition Bulletin 29, 325–332.CrossRefGoogle Scholar
Glasser, F, Ferlay, A, Chilliard, Y 2008. Oilseed lipid supplements and fatty acid composition of cow milk: a meta-analysis. Journal of Dairy Science 91, 4687–4703.CrossRefGoogle ScholarPubMed
Goel, G, Arvidsson, K, Vlaeminck, B, Bruggeman, G, Deschepper, K, Fievez, V 2009. Effects of capric acid on rumen methanogenesis and biohydrogenation of linoleic and α-linolenic acid. Animal 3, 810–816.CrossRefGoogle ScholarPubMed
Griinari, JM, Corl, BA, Lacy, SH, Chouinard, PY, Nurmela, KV, Bauman, DE 2000. Conjugated linoleic acid is synthesized endogenously in lactating dairy cows by delta(9)-desaturase. The Journal of Nutrition 130, 2285–2291.CrossRefGoogle ScholarPubMed
Harfoot, CG 1981. Lipid metabolism in the rumen. In Lipid metabolism in ruminant animals (ed. WW Christie), pp. 21–55. Pergamon Press, Oxford, UK.CrossRefGoogle Scholar
Harfoot, CG, Hazlewood, GP 1997. Lipid metabolism in the rumen. In The rumen microbial ecosystem (ed. PN Hobson and CS Stewart), pp. 382–426. Chapman & Hall, London, UK.CrossRefGoogle Scholar
Hazlewood, GP, Dawson, RMC 1975. Isolation and properties of a phospholipid-hydrolysing bacterium from ovine rumen fluid. Journal of General Microbiology 89, 163–174.CrossRefGoogle Scholar
Hazlewood, G, Dawson, RMC 1979. Characteristics of a lipolytic and fatty acid – requiring Butyrivibrio sp isolated from the ovine rumen. Journal of General Microbiology 112, 15–27.CrossRefGoogle ScholarPubMed
Hazlewood, GP, Kemp, P, Lander, D, Dawson, RMC 1976. C18 unsaturated fatty acid hydrogenation patterns of some rumen bacteria and their ability to hydrolyse exogenous phospholipid. The British Journal of Nutrition 35, 293–297.CrossRefGoogle ScholarPubMed
Henderson, C 1968. A study of the lipase of Anaerovibrio lipolytica: a rumen bacterium. PhD, University of Aberdeen, Aberdeen.Google Scholar
Henderson, C 1971. A study of the lipase of Anaerovibrio lipolytica: a rumen bacterium. Journal of General Microbiology 65, 81–89.CrossRefGoogle ScholarPubMed
Henderson, C 1973. The effects of fatty acids on pure cultures of rumen bacteria. Journal of Agricultural Science 81, 107–112.CrossRefGoogle Scholar
Henderson, C, Hodgkiss, W 1973. An electron microscopic study of Anaerovibrio lipolytica (strain 5s) and its lipolytic enzyme. Journal of General Microbiology 76, 389–393.CrossRefGoogle ScholarPubMed
Hess, HD, Beuret, RA, Lötscher, M, Hindrichsen, IK, Machmüller, A, Carulla, JE, Lascano, CE, Kreuzer, M 2004. Ruminal fermentation, methanogenesis and nitrogen utilization of sheep receiving tropical grass hay-concentrate diets offered with Sapindus saponaria fruits and Cratylia argentea foliage. Animal Science 79, 177–189.CrossRefGoogle Scholar
Hino, T, Russell, JB 1985. Effect of reducing-equivalent disposal and NADH/NAD on deamination of amino acids by intact rumen microorganisms and their cell extracts. Applied and Environmental Microbiology 50, 1368–1374.CrossRefGoogle ScholarPubMed
Hobson, PN, Mann, SO 1961. The isolation of glycerol-fermenting and lipolytic bacteria from the rumen of the sheep. Journal of General Microbiology 25, 227–240.CrossRefGoogle ScholarPubMed
Hungate, RE 1966. The rumen and its microbes. New York academic press, New York, NY, USA.Google Scholar
Hungate, RE, Reichl, J, Prins, R 1971. Parameters of rumen fermentation in a continuously fed sheep: evidence of a microbial rumination pool. Applied Microbiology 22, 1104–1113.CrossRefGoogle Scholar
Huws, SA, Kim, EJ, Kingston-Smith, AH, Lee, MRF, Muetzel, SM, Cookson, AR, Newbold, CJ, Wallace, RJ, Scollan, ND 2009a. Rumen protozoa are rich in polyunsaturated fatty acids due to the ingestion of chloroplasts. FEMS Microbiology Ecology 69, 461–471.CrossRefGoogle Scholar
Huws, S, Kim, EJ, Lee, MRF, Pinloche, E, Wallace, RJ, Scollan, ND 2009b. The effects of incremental fish oil supplementation on bacterial populations in the rumen. In Ruminant physiology: digestion, metabolism, and effects of nutrition on reproduction and welfare (ed. Y Chilliard, F Glasser, Y Faulconnier, F Bocquier, I Veissier and M Doreau), pp. 82–83. Wageningen Academic Publishers, The Netherlands.Google Scholar
Jarvis, GN, Strompl, C, Moore, ERB, Thiele, JH 1998. Isolation and characterisation of obligately anaerobic, lipolytic bacteria from the rumen of red deer. Systematic and Applied Microbiology 21, 135–143.CrossRefGoogle ScholarPubMed
Jenkins, TC, Wallace, RJ, Moate, PJ, Mosley, EE 2008. Recent advances in biohydrogenation of unsaturated fatty acids within the rumen microbial ecosystem. Journal of Animal Science 86, 397–412.CrossRefGoogle ScholarPubMed
Jordan, E, Lovett, DK, Monahan, FJ, Callan, J, Flynn, B, O’Mara, FP 2006. Effect of refined coconut oil or copra meal on methane output and on intake and performance of beef heifers. Journal of Animal Science 84, 162–170.CrossRefGoogle ScholarPubMed
Katz, I, Keeney, M 1966. Characterization of the octadecenoic acids in rumen digesta and rumen bacteria. Journal of Dairy Science 49, 962–966.CrossRefGoogle ScholarPubMed
Keeney, M 1970. Lipid metabolism in the rumen. In Physiology and metabolism in the ruminant (ed. AT Phillipson), pp. 489–503. Oriel Press, Newcastle-upon-Tyne.Google Scholar
Kemp, P, White, RW, Lander, DJ 1975. The hydrogenation of unsaturated fatty acids by five bacterial isolates from the sheep rumen, including a new species. Journal of General Microbiology 90, 100–114.CrossRefGoogle ScholarPubMed
Kennelly, JJ 1996. The fatty acid composition of milk fat as influenced by feeding oilseeds. Animal Feed Science and Technology 60, 137–152.CrossRefGoogle Scholar
Kepler, CR, Hirons, KP, McNeill, JJ, Tove, SB 1966. Intermediates and products of the biohydrogenation of linoleic acid by Butyrivibrio fibrisolvens. The Journal of Biological Chemistry 241, 1350–1354.CrossRefGoogle Scholar
Kim, YJ, Liu, RH, Rychlik, JL, Russell, JB 2002. The enrichment of a ruminal bacterium (Megasphaera elsdenii YJ-4) that produces the trans-10, cis-12 isomer of conjugated linoleic acid. Journal of Applied Microbiology 92, 976–982.CrossRefGoogle ScholarPubMed
Kim, EJ, Huws, SA, Lee, MRF, Wood, JD, Muetzel, SM, Wallace, RJ, Scollan, ND 2008. Fish oil increases the duodenal flow of long chain polyunsaturated fatty acids and trans-11 18:1 and decreases 18:0 in steers via changes in the rumen bacteria community. The Journal of Nutrition 138, 889–896.CrossRefGoogle Scholar
Klopfenstein, TJ, Purser, DB, Tyznik, WJ 1966. Effects of defaunation on feed digestibility rumen metabolism and blood metabolites. Journal of Animal Science 25, 765–773.CrossRefGoogle ScholarPubMed
Koike, S, Yabuki, H, Kobayashi, Y 2007. Validation and application of real-time polymerase chain reaction assays for representative rumen bacteria. Animal Science Journal 78, 135–141.CrossRefGoogle Scholar
Krueger, NA, Anderson, RC, Callaway, TR, Edrington, TS, Beier, RC, Shelver, WL, Nisbet, DJ 2009. Effects of antibodies and glycerol as potential inhibitors of ruminal lipase activity. In Proceedings of the 2009 Conference on Gastrointestinal Function, April 20-22, Chicago, IL, 575pp.Google Scholar
Lassey, KR 2008. Livestock methane emission and its perspective in the global methane cycle. Australian Journal of Experimental Agriculture 48, 114–118.CrossRefGoogle Scholar
Latham, MJ, Wolin, MJ 1977. Fermentation of cellulose by Ruminococcus flavefaciens in the presence and absence of Methanobacterium ruminantium. Applied and Environmental Microbiology 34, 297–301.CrossRefGoogle ScholarPubMed
Lee, MRF, Theodorou, MK, Chow, TT, Scollan, ND 2002. In-vitro evidence for plant enzyme mediated lipolysis in the rumen. Proceedings of the Nutrition Society 61, 103A.Google Scholar
Lee, MRF, Harris, LJ, Dewhurst, RJ, Merry, RJ, Scollan, ND 2003. The effect of clover silages on long chain fatty acid rumen transformations and digestion in beef steers. Animal Science 76, 491–501.CrossRefGoogle Scholar
Lee, MRF, Winters, AL, Scollan, ND, Dewhurst, RJ, Theodorou, MK, Minchin, FR 2004. Plant-mediated lipolysis and proteolysis in red clover with different polyphenol oxidase activities. Journal of the Science of Food and Agriculture 84, 3061–3070.CrossRefGoogle Scholar
Lee, MRF, Tweed, JKS, Moloney, AP, Scollan, ND 2005. The effects of fish oil supplementation on rumen metabolism and the biohydrogenation of unsaturated fatty acids in beef steers given diets containing sunflower oil. Animal Science 80, 361–367.CrossRefGoogle Scholar
Lee, MRF, Parfitt, LJ, Scollan, ND, Minchin, FR 2007. Lipolysis in red clover with different polyphenol oxidase activities in the presence and absence of rumen fluid. Journal of the Science of Food and Agriculture 87, 1308–1314.CrossRefGoogle Scholar
Lennarz, WJ 1966. Lipid metabolism in the bacteria. Advances in Lipid Research 4, 175–225.CrossRefGoogle ScholarPubMed
Lila, ZA, Mohammed, N, Kanda, S, Kamada, T, Itabashi, H 2003. Effect of sarsaponin on ruminal fermentation with particular reference to methane production in vitro. Journal of Dairy Science 86, 3330–3336.CrossRefGoogle ScholarPubMed
Liu, K, Wang, J, Bu, D, Zhao, S, McSweeney, C, Yu, P, Li, D 2009. Isolation and biochemical characterization of two lipases from a metagenomic library of China Holstein cow rumen. Biochemical and Biophysical Research Communications 385, 605–611.CrossRefGoogle ScholarPubMed
Lock, AL, Teles, BM, Perfield, JW, Bauman, DE, Sinclair, LA 2006. A conjugated linoleic acid supplement containing trans-10, cis-12 reduces milk fat synthesis in lactating sheep. Journal of Dairy Science 89, 1525–1532.CrossRefGoogle ScholarPubMed
Loor, JJ, Ueda, K, Ferlay, A, Chilliard, Y, Doreau, M 2005. Intestinal flow and digestibility of trans fatty acids and conjugated linoleic acids (CLA) in dairy cows fed a high-concentrate diet supplemented with fish oil, linseed oil, or sunflower oil. Animal Feed Science and Technology 119, 203–225.CrossRefGoogle Scholar
Lourenço, M, Van Ranst, G, Fievez, V 2005. Differences in extent of lipolysis in red or white clover and ryegrass silages in relation to polyphenol oxidase activity. Communications in Agricultural and Applied Biological Sciences 70, 169–172.Google ScholarPubMed
Lourenço, M, Cardozo, PW, Calsamiglia, S, Fievez, V 2008a. Effects of saponins, quercetin, eugenol, and cinnamaldehyde on fatty acid biohydrogenation of forage polyunsaturated fatty acids in dual-flow continuous culture fermenters. Journal of Animal Science 86, 3045–3053.CrossRefGoogle ScholarPubMed
Lourenço, M, Van Ranst, G, Vlaeminck, B, De Smet, S, Fievez, V 2008b. Influence of different dietary forages on the fatty acid composition of rumen digesta as well as ruminant meat and milk. Animal Feed Science and Technology 145, 418–435.CrossRefGoogle Scholar
Lourenço, M, Falchero, L, Tava, A, Fievez, V 2009. Alpine vegetation essential oils and their effect on rumen lipid metabolism in vitro. In Ruminant physiology: digestion, metabolism, and effects of nutrition on reproduction and welfare (ed. Y Chilliard, F Glasser, Y Faulconnier, F Bocquier, I Veissier and M Doreau), pp. 88–89. Wageningen Academic Publishers, The Netherlands.Google Scholar
Macheboeuf, D, Morgavi, DP, Papon, Y, Mousset, JL, Arturo-Schaan, M 2008. Dose-response effects of essential oils on in vitro fermentation activity of the rumen microbial population. Animal Feed Science and Technology 145, 335–350.CrossRefGoogle Scholar
Maia, MRG, Chaudhary, LC, Figueres, L, Wallace, RJ 2007. Metabolism of polyunsaturated fatty acids and their toxicity to the microflora of the rumen. Antonie van Leeuwenhoek 91, 303–314.CrossRefGoogle Scholar
Maia, MRG, Chaudhary, LC, Bestwick, CS, Richardson, AJ, McKain, N, Larson, TR, Graham, IA, Wallace, RJ 2010. Toxicity of unsaturated fatty acids to the biohydrogenating ruminal bacterium, Butyrivibrio fibrisolvens. BMC Microbiology 10, 52.CrossRefGoogle Scholar
Makkar, HPS 2003. Effects and fate of tannins in ruminant animals, adaptation to tannins, and strategies to overcome detrimental effects of feeding tannin-rich diets. Small Ruminant Research 49, 241–256.CrossRefGoogle Scholar
Makkar, HPS, Becker, K 1997. Degradation of quillaja saponins by mixed cultures of rumen microbes. Letters in Applied Microbiology 25, 243–245.CrossRefGoogle ScholarPubMed
Makkar, HPS, Becker, K, Abel, HJ, Szegletti, C 1995a. Degradation of condensed tannins by rumen microbes exposed to quebracho tannins (QT) in rumen simulation technique (RUSITEC) and effects of QT on fermentation processes in the RUSITEC. Journal of the Science of Food and Agriculture 69, 495–500.CrossRefGoogle Scholar
Makkar, HPS, Blümmel, M, Becker, K 1995b. In vitro effects and interactions of tannins and saponins and fate of tannins in rumen. Journal of the Science of Food and Agriculture 69, 481–493.CrossRefGoogle Scholar
Makkar, HPS, Sen, S, Blümmel, M, Becker, K 1998. Effects of fractions containing saponins from Yucca schidigera, Quillaja saponaria and Acacia auriculoformis on rumen fermentation. Journal of Agricultural and Food Chemistry 46, 4324–4328.CrossRefGoogle Scholar
Malecky, M, Broudiscou, LP 2009. Disappearance of nine monoterpenes exposed in vitro to the rumen microflora of dairy goats: effects of inoculum source, redox potential, and vancomycin. Journal of Animal Science 87, 1366–1373.CrossRefGoogle Scholar
Malecky, M, Fedele, V, Broudiscou, LP 2009. In vitro degradation by mixed rumen bacteria of 17 mono- and sesquiterpenes typical of winter and spring diets of goats on Basilitica rangelands (southern Italy). Journal of the Science of Food and Agriculture 89, 531–536.CrossRefGoogle Scholar
Marmer, WN, Maxwell, RJ, Wagner, DG 1985. Effects of dietary monensin on bovine fatty-acid profiles. Journal of Agricultural and Food Chemistry 33, 67–70.CrossRefGoogle Scholar
Martin, C, Morgavi, DP, Doreau, M 2009. Methane mitigation in ruminants: from microbe to the farm scale. Animal, doi:10.1017/S1751731109990620.Google Scholar
Matsumoto, M, Kobayashi, T, Takenaka, A, Itabashi, H 1991. Defaunation effects of medium-chain fatty acids and their derivatives on goat rumen protozoa. The Journal of General and Applied Microbiology 37, 439–445.CrossRefGoogle Scholar
McIntosh, FM, Williams, P, Losa, R, Wallace, RJ, Beever, DA, Newbold, CJ 2003. Effects of essential oils on ruminal microorganisms and their protein metabolism. Applied and Environmental Microbiology 69, 5011–5014.CrossRefGoogle ScholarPubMed
McKain, N, Wood, TA, Shen, X, Atasoglu, C, Wallace, RJ 2008. Chrysanthemum coronarium as a possible modulator of biohydrogenation of fatty acids. In the rumen 6th INRA-RRI symposium, ‘gut microbiome—functionality, interaction with the host and impact on the environment’, Clermont-Ferrand, France, 74pp.Google Scholar
McKain, N, Shingfield, KJ, Wallace, RJ 2010. Metabolism of conjugated linoleic acids and 18:1 fatty acids by ruminal bacteria: products and mechanisms. Microbiology 156, 579–588.CrossRefGoogle ScholarPubMed
Mensink, RP, Zock, PL, Kester, AD, Katan, MB 2003. Effects of dietary fatty acids and carbohydrates on the ratio of serum total HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials. American Journal of Clinical Nutrition 77, 1146–1155.CrossRefGoogle ScholarPubMed
Moon, CD, Pacheco, DM, Kelly, WJ, Leahy, SC, Li, D, Kopecny, J, Attwood, GT 2008. Reclassification of Clostridium proteoclasticum as Butyrivibrio proteoclasticus comb. nov., a butyrate producing ruminal bacterium. International Journal of Systematic and Evolutionary Microbiology 58, 2041–2045.CrossRefGoogle Scholar
Mosley, SA, Mosley, EE, Hatch, B, Szasz, JI, Corato, A, Zacharias, N, Howes, D, McGuire, MA 2007. Effect of varying levels of fatty acids from palm oil on feed intake and milk production in Holstein cows. Journal of Dairy Science 90, 987–993.CrossRefGoogle ScholarPubMed
Mozaffarian, D, Katan, MB, Ascherio, A, Stampfer, MJ, Willett, WC 2006. Trans fatty acids and cardiovascular disease. The New England Journal of Medicine 354, 1601–1613.CrossRefGoogle ScholarPubMed
Nagaraja, TG, Newbold, CJ, Van Nevel, CJ, Demeyer, DI 1997. Manipulation of ruminal fermentation. In The rumen microbial ecosystem (ed. PN Hobson and CS Stewart), pp. 523–632. Chapman & Hall, London, UK.CrossRefGoogle Scholar
Nam, IS, Garnsworthy, PC 2007a. Biohydrogenation of linoleic acid by rumen fungi compared with rumen bacteria. Journal of Applied Microbiology 103, 551–556.CrossRefGoogle ScholarPubMed
Nam, IS, Garnsworthy, PC 2007b. Factors influencing biohydrogenation and conjugated linoleic acid production by mixed rumen fungi. Journal of Microbiology 45, 199–204.Google ScholarPubMed
Odongo, NE, Or-Rashid, MM, Kebreab, E, France, J, McBride, BW 2007. Effect of supplementing myristic acid in dairy cow rations on ruminal methanogenesis and fatty acid profile in milk. Journal of Dairy Science 90, 1851–1858.CrossRefGoogle ScholarPubMed
Offer, NW, Marsden, M, Phipps, RH 2001. Effect of oil supplementation of a diet containing a high concentration of starch on levels of trans fatty acids and conjugated linoleic acids in bovine milk. Animal Science 73, 533–540.CrossRefGoogle Scholar
Omar Faruque, AJM, Jarvis, BDW, Hawke, JC 1974. Studies on Rumen Metabolism. IX. Contribution of plant lipases to release of free fatty-acids in rumen. Journal of the Science of Food and Agriculture 25, 1313–1328.CrossRefGoogle Scholar
Or-Rashid, MM, Alzahal, O, McBride, BW 2008. Studies on the production of conjugated linoleic acid from linoleic and VA by mixed protozoa. Applied Microbial and Cell Physiology 81, 533–541.Google Scholar
Paillard, D, McKain, N, Chaudhary, LC, Walker, ND, Pizette, F, Koppova, I, McEwan, NR, Kopecny, J, Vercoe, PE, Louis, P, Wallace, RJ 2007. Relation between phylogenetic position, lipid metabolism and butyrate production by different Butyrivibrio-like bacteria from the rumen. Antonie Van Leeuwenhoek 91, 417–422.CrossRefGoogle ScholarPubMed
Palmquist, DL 1988. The feeding value of fats. In Feed science (ed. ER Orskov), pp. 293–311. Elsevier Science Publisher, Amsterdam, Netherlands.Google Scholar
Palmquist, DL, Lock, AL, Shingfield, KJ, Bauman, DE 2005. Biosynthesis of conjugated linoleic acid in ruminants and humans. Advances in Food and Nutrition Research 50, 179–217.CrossRefGoogle ScholarPubMed
Pariza, MW 2004. Perspective on the safety and effectiveness of conjugated linoleic acid. The American Journal of Clinical Nutrition 79, 1132S–1136S.CrossRefGoogle ScholarPubMed
Pen, B, Takaura, K, Yamaguchi, S, Asa, R, Takahashi, J 2007. Effects of Yucca schidigera and Quillaja saponaria with or without β 1-4 galacto-oligosaccharides on ruminal fermentation, methane production and nitrogen utilization in sheep. Animal Feed Science and Technology 138, 75–88.CrossRefGoogle Scholar
Pfeffer, E, Hristov, AN 2007. Interactions between cattle and the environment: a general introduction. In Nitrogen and phosphorus nutrition of cattle (ed. E Pfeffer and AN Hristov), pp. 1–12. CABI Publishing, Wallingford, Oxon, UK.Google Scholar
Polan, CE, McNeill, JJ, Tove, SB 1964. Biohydrogenation of unsaturated fatty acids by rumen bacteria. Journal of Bacteriology 88, 1056–1064.CrossRefGoogle ScholarPubMed
Potu, RB, AbuGhazaleh, AA, Jones, KL, Atkinson, RL, Hastings, D, Haddock, JD, Ibrahim, S 2009. Effect of dietary lipids on selected strains of ruminal bacteria. Journal of Dairy Science 92 (E-suppl. 1), 457.Google Scholar
Prins, RA, Lankhorst, A, Van der Meer, P, Van Nevel, CJ 1975. Some characteristics of Anaerovibrio lipolytica, a rumen lipolytic organism. Antonie van Leeuwenhoek 41, 1–11.CrossRefGoogle ScholarPubMed
Puchala, R, Min, BR, Goetsch, AL, Sahlu, T 2005. The effect of a condensed tannin-containing forage on methane emission by goats. Journal of Animal Science 83, 182–186.CrossRefGoogle ScholarPubMed
Rattray, RM, Craig, AM 2007. Molecular characterization of sheep ruminal enrichments that detoxify pyrrolizidine alkaloids by denaturing gradient gel electrophoresis and cloning. Microbial Ecology 54, 264–275.CrossRefGoogle ScholarPubMed
Roth, S, Steingass, H, Drochner, W 2001. Wirkungen von tanninextracten auf die parameter der pansenfermentation in vitro. Proceedings 10th Conference on Nutrition of Domestic Animals-Adolf Pen Zadravec-Erjavec Days, Radenci, Slovenia, pp. 64–70.Google Scholar
Russell, JB, Wallace, RJ 1997. Energy yielding and consuming reactions. In The rumen microbial ecosystem (ed. PN Hobson and CS Stewart), pp. 185–215. Chapman & Hall, London, UK.Google Scholar
Russell, JB, Onodera, R, Hino, T 1991. Ruminal protein fermentation: new perspectives on previous contradictions. In Physiological aspects of digestion and metabolism in ruminants (ed. T Tsuda, Y Sasaki and R Kawashima), pp. 681–697. Academic Press, San Diego.CrossRefGoogle Scholar
Saebø, A, Saebø, PC, Griinari, JM, Shingfield, KJ 2005. Effect of abomasal infusions of geometric isomers of 10, 12 conjugated linoleic acid on milk fat synthesis in dairy cows. Lipids 40, 823–832.CrossRefGoogle ScholarPubMed
Sato, H, Karitani, A 2009. Anticoccidial versus ruminal defaunation efficacy of medium chain triglyceride depending on delivery route in calves. The Journal of Veterinary Medical Science 71, 1243–1245.CrossRefGoogle ScholarPubMed
Sauer, FD, Fellner, V, Kinsman, R, Kramer, JKG, Jackson, HA, Lee, AJ, Chen, S 1998. Methane output and lactation response in Holstein cattle with monensin or unsaturated fat added to the diet. Journal of Animal Science 76, 906–914.CrossRefGoogle ScholarPubMed
Schmidely, R, Glasser, F, Doreau, M, Sauvant, D 2008. Digestion of fatty acids in ruminants: a meta-analysis of flows and variation factors. 1. Total fatty acids. Animal 2, 677–690.CrossRefGoogle ScholarPubMed
Scollan, N, Hocquette, JF, Nuernberg, K, Dannenberger, D, Richardson, I, Moloney, A 2006. Innovations in beef productions systems that enhance the nutritional and health value of beef lipids and their relationship with meat quality. Meat Science 74, 17–33.CrossRefGoogle ScholarPubMed
Shingfield, KJ, Griinari, JM 2007. Role of biohydrogenation intermediates in milk fat depression. European Journal of Lipid Science and Technology 109, 799–816.CrossRefGoogle Scholar
Shingfield, KJ, Ahvenjarvi, S, Toivonen, V, Arola, A, Nurmela, KVV, Huhtanen, P, Griinari, JM 2003. Effect of dietary fish oil on biohydrogenation of fatty acids and milk fatty acid content in cows. Animal Science 77, 165–179.CrossRefGoogle Scholar
Shingfield, KJ, Reynolds, CK, Hervás, G, Griinari, JM, Grandison, AS, Beever, DE 2006. Examination of the persistency of milk fatty acid composition responses to fish oil and sunflower oil in the diet of dairy cows. Journal of Dairy Science 89, 714–732.CrossRefGoogle ScholarPubMed
Shingfield, KJ, Saebø, A, Saebø, PC, Toivonen, V, Griinari, JM 2009. Effect of abomasal infusions of a mixture of octadecenoic acids on milk fat synthesis in lactating cows. Journal of Dairy Science 92, 4317–4329.CrossRefGoogle ScholarPubMed
Simopoulos, AP 2004. Omega-6/omega-3 essential fatty acid ratio and chronic diseases. Food Reviews International 20, 77–90.CrossRefGoogle Scholar
Singh, S, Hawke, JC 1979. The in vitro lipolysis and biohydrogenation of monogalactosyldiglyceride by whole rumen contents and its fractions. Journal of the Science of Food and Agriculture 30, 603–612.CrossRefGoogle ScholarPubMed
Sliwinski, BJ, Soliva, CR, Mächmuller, A, Kreuzer, M 2002. Efficacy of plant extracts rich in secondary constituents to modify rumen fermentation. Animal Feed Science and Technology 101, 101–114.CrossRefGoogle Scholar
Spanghero, M, Zanfi, C, Fabbro, E, Scicutella, N, Camellini, C 2008. Effects of a blend of essential oils on some end products of in vitro rumen fermentation. Animal Feed Science and Technology 145, 364–374.CrossRefGoogle Scholar
Stern, MD, Hoover, WH, Leonard, JB 1977. Ultrastructure of rumen holotrichs by electron microscopy. Journal of Dairy Science 60, 911–918.CrossRefGoogle ScholarPubMed
Stewart, CS 1977. Factors affecting the cellulolytic activity of rumen contents. Applied and Environmental Microbiology 33, 497–502.CrossRefGoogle ScholarPubMed
Stewart, CS, Flint, HJ, Bryant, MP 1997. The rumen bacteria. In The rumen microbial ecosystem (ed. PN Hobson and CS Stewart), pp. 10–72. Chapman & Hall, London, UK.CrossRefGoogle Scholar
Szumacher-Strabel, M, Martin, SA, Potkanski, A, Cieslak, A, Kowalczyk, J 2004. Changes in fermentation processes as the effect of vegetable oil supplementation in in vitro studies. Journal of Animal and Feed Sciences 13, 215–218.CrossRefGoogle Scholar
Tajima, K, Aminov, RI, Nagamine, T, Matsui, H, Nakamura, M, Benno, Y 2001. Diet-dependent shifts in the bacterial population of the rumen revealed with real-time PCR. Applied and Environmental Microbiology 67, 2766–2774.CrossRefGoogle ScholarPubMed
Teferedegne, B, Osuji, PO, Odenyo, AA, Wallace, RJ, Newbold, CJ 1999. Influence of foliage of different accessions of the sub-tropical leguminous tree, Sesbania sesban, on ruminal protozoa in Ethiopian and Scottish sheep. Animal Feed Science and Technology 78, 11–20.CrossRefGoogle Scholar
Terefedegne, B 2000. New perspectives on the use of tropical plants to improve ruminant nutrition. Proceedings of Nutrition Society 59, 209–214.CrossRefGoogle Scholar
Tsuzuki, T, Tokuyama, Y, Igarashi, M, Miyazawa, T 2004. Tumor growth suppression by alpha-eleostearic acid, a linolenic acid isomer with a conjugated triene system, via lipid peroxidation. Carcinogenesis 25, 1417–1425.CrossRefGoogle ScholarPubMed
Van de Vossenberg, JL, Joblin, KN 2003. Biohydrogenation of C18 unsaturated fatty acids to stearic acid by a strain of Butyrivibrio hungatei from the bovine rumen. Letters in Applied Microbiology 37, 424–428.CrossRefGoogle ScholarPubMed
Van Nevel, CJ, Demeyer, DI 1996. Influence of pH on lipolysis and biohydrogenation of soybean oil by rumen contents in vitro. Reproduction, Nutrition, Development 36, 53–63.CrossRefGoogle ScholarPubMed
Van Ranst, G, Fievez, V, Vandewalle, M, De Riek, J, Van Bockstaele, E 2009. In vitro study of red clover polyphenol oxidase activity, activation, and effect on measured lipase activity and lipolysis. Journal of Agricultural and Food Chemistry 57, 6611–6617.CrossRefGoogle ScholarPubMed
Váradyová, Z, Kišidayová, S, Siroka, P, Jalč, D 2007. Fatty acid profiles of rumen fluid from sheep fed diets supplemented with various oils and effect on the rumen ciliate population. Czech Journal of Animal Science 52, 399–406.CrossRefGoogle Scholar
Vasta, V, Makkar, HPS, Mele, M, Priolo, A 2009. Ruminal biohydrogenation as affected by tannins in vitro. The British Journal of Nutrition 102, 82–92.CrossRefGoogle ScholarPubMed
Walker, ND, Newbold, CJ, Wallace, RJ 2005. Nitrogen metabolism in the rumen. In Nitrogen and phosphorus nutrition in cattle (ed. E Pfeffer and A Hristov), pp. 71–115. CAB International, Wallingford, UK.Google Scholar
Wallace, RJ, Arthaud, L, Newbold, CJ 1994. Influence of Yucca schidigera extract on ruminal ammonia concentrations and ruminal microorganisms. Applied and Environmental Microbiology 60, 1762–1767.CrossRefGoogle ScholarPubMed
Wallace, RJ, Chaudhary, LC, McKain, N, McEwan, NR, Richardson, AJ, Vercoe, PE, Walker, ND, Paillard, D 2006. Clostridium proteoclasticum: a ruminal bacterium that forms stearic acid from linoleic acid. FEMS Microbiology Letters 265, 195–201.CrossRefGoogle Scholar
Wallace, RJ, McKain, N, Shingfield, KJ, Devillard, E 2007. Isomers of conjugated linoleic acids are synthesized via different mechanisms in ruminal digesta and bacteria. Journal of Lipid Research 48, 2247–2254.CrossRefGoogle ScholarPubMed
Wąsowska, I, Maia, MRG, Niedzwiedzka, KM, Czauderna, M, Ramalho Ribeiro, JMC, Devillard, E, Shingfield, KJ, Wallace, RJ 2006. Influence of fish oil on ruminal biohydrogenation of C18 unsaturated fatty acids. The British Journal of Nutrition 95, 1199–1211.CrossRefGoogle ScholarPubMed
Weimer, PJ 1996. Why don’t ruminal bacteria digest cellulose faster? Journal of Dairy Science 79, 1496–1502.CrossRefGoogle ScholarPubMed
Weimer, PJ, Stevenson, DM, Mertens, DR 2010. Shifts in bacterial community composition in the rumen of lactating dairy cows under milk fat-depressing conditions. Journal of Dairy Science 93, 265–278.CrossRefGoogle ScholarPubMed
Weller, RA, Pilgrim, AF 1974. Passage of protozoa and volatile fatty acids from the rumen of the sheep and from a continuous in vitro fermentation system. The British Journal of Nutrition 32, 341–351.CrossRefGoogle ScholarPubMed
Whigham, LD, Cook, ME, Atkinson, RL 2000. Conjugated linoleic acid: implications for human health. Pharmacological Research 42, 503–510.CrossRefGoogle ScholarPubMed
World Health Organization (WHO) 2003. Diet, nutrition and the prevention of chronic diseases. Technical report series 916. WHO, Geneva.Google Scholar
Wilde, PF, Dawson, RM 1966. The biohydrogenation of alpha-linolenic acid and oleic acid by rumen micro-organisms. Biochemical Journal 98, 469–475.CrossRefGoogle ScholarPubMed
Williams, AG, Coleman, GS 1992. The Rumen Protozoa. Springer-Verlag, New York, NY, USA.CrossRefGoogle Scholar
Williams, AG, Coleman, GS 1997. The rumen protozoa. In The rumen microbial ecosystem (ed. PN Hobston and CS Stewart), pp. 73–139. Chapman and Hall, London, UK.CrossRefGoogle Scholar
Wina, E, Muetzel, S, Becker, K 2005. The impact of saponins or saponin-containing plant materials on ruminant production – a review. Journal of Agricultural and Food Chemistry 53, 8093–8105.CrossRefGoogle ScholarPubMed
Wolin, MJ, Miller, TL, Stewart, CS 1997. Microbe-microbe interactions. In The rumen microbial ecosystem (ed. PN Hobson and CS Stewart), pp. 467–491. Chapman & Hall, London, UK.CrossRefGoogle Scholar
Woodward, SL, Waghorn, GC, Ulyatt, MJ, Lassey, KR 2001. Early indications that feeding Lotus will reduce methane emission from ruminants. Proceedings of the New Zealand Society of Animal Production 61, 23–26.Google Scholar
Woodward, SL, Waghorn, GC, Lassey, KR, Laboyrie, PG 2002. Does feeding sulla (Hedysarum coronarium) reduce methane emission from dairy cows? Proceedings of the New Zealand Society of Animal Production 62, 227–230.Google Scholar
Wright, DE 1959. Hydrogenation of lipids by rumen protozoa. Nature 184, 875–876.CrossRefGoogle ScholarPubMed
Wright, DE 1960. Pectic enzymes in rumen protozoa. Archives of Biochemistry and Biophysiscs 86, 251–254.CrossRefGoogle ScholarPubMed
Wright, DE 1961. Bloat in cattle. XX. Lipase activity of rumen microorganisms. New Zealand Journal of Agricultural Research 4, 216–223.CrossRefGoogle Scholar
Yabuuchi, Y, Matsushita, Y, Otsuka, H, Fukamachi, K, Kobayashi, Y 2006. Effects of supplemental lauric acid-rich oils in high grain diet on in vitro rumen fermentation. Animal Science Journal 77, 300–307.CrossRefGoogle Scholar
Yáñez-Ruiz, DR, Scollan, ND, Merry, RJ, Newbold, CJ 2006. Contribution of rumen protozoa to duodenal flow of nitrogen, conjugated linoleic acid and VA in steers fed silages differing in their water-soluble carbohydrate content. The British Journal of Nutrition 96, 861–869.CrossRefGoogle ScholarPubMed
Yáñez-Ruiz, DR, Williams, S, Newbold, CJ 2007. The effect of absence of protozoa on rumen biohydrogenation and the fatty acid composition of lamb muscle. The British Journal of Nutrition 97, 938–948.CrossRefGoogle ScholarPubMed
Yang, SL, Bu, DP, Wang, JQ, Hu, ZY, Li, D, Wei, HY, Zhou, LY, Loor, JJ 2009. Soybean oil and linseed oil supplementation affect profiles of ruminal microorganisms in dairy cows. Animal 3, 1562–1569.CrossRefGoogle ScholarPubMed
Zhang, CM, Guo, YQ, Yuan, ZP, Wu, YM, Wang, JK, Liu, JX, Zhu, WY 2008. Effect of octadeca carbon fatty acids on microbial fermentation, methanogenesis and microbial flora in vitro. Animal Feed Science and Technology 146, 259–269.CrossRefGoogle Scholar