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Infection by the Fungal Pathogen Colletotrichum coccodes Affects Velvetleaf (Abutilon theophrasti)-Soybean Competition in the Field
- Antonio Ditommaso, Alan K. Watson, Steve G. Hallett
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- Journal:
- Weed Science / Volume 44 / Issue 4 / December 1996
- Published online by Cambridge University Press:
- 12 June 2017, pp. 924-933
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Field research was conducted from 1990 through 1992 to evaluate the effect of the fungal pathogen, Colletotrichum coccodes, on velvetleaf intra- and interspecific (with soybean) competition across a range of monoculture and 1:1 mixture densities. In pure stand, application of this velvetleaf foliar pathogen had little impact on seed yield of the weed. In these plots, velvetleaf intraspecific competition stimulated vertical growth and favored the rapid replacement of diseased leaf tissue that had prematurely senesced. In mixtures, however, C. coccodes inoculation differentially influenced the yield of both species. In two of three years, C. coccodes inoculation reduced velvetleaf seed yields by, an average, 60% compared with yields for control (uninoculated) plants. Velvetleaf suffered greater yield losses from soybean interspecific competition in the presence of C. coccodes, especially at the lower planting densities. The decline in velvetleaf yield was primarily attributed to the stunting effect of the pathogen, which allowed soybean plants to grow above the weed. Consequently, soybean yield losses within inoculated mixture plots were generally lower than for control plots, although significant increases (23%) in soybean yield were recorded only in 1992. The inoculation treatment had relatively little impact on the number of seeds produced per fruit or seed unit weight in both species regardless of whether plants were grown in monocultures or in mixtures. The finding that C. coccodes has only a limited effect on velvetleaf performance in pure stand, while having a significantly greater effect in a competitive environment with a soybean crop, has important ramifications as to the value and accuracy of initial efficacy testing that rates potential biocontrol agents based solely on their effect within pure stands of the target weed.
Performance of Colletotrichum dematium for the Control of Fireweed (Epilobium angustifolium) Improved with Formulation
- Christian Léger, Steven G. Hallett, Alan K. Watson
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- Journal:
- Weed Technology / Volume 15 / Issue 3 / September 2001
- Published online by Cambridge University Press:
- 20 January 2017, pp. 437-446
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The potential of Colletotrichum dematium f.sp. epilobii (ATCC 20981) to control fireweed (Epilobium angustifolium) was investigated. Under controlled environment conditions, plant age, inoculum density, length of the dew period, and temperature during the dew period affected the efficacy of C. dematium f.sp. epilobii. Seedlings sprayed with 1 × 109 conidia/m2 sustained the most damage. Susceptibility decreased with increasing plant age, and 10-wk-old plants were slightly affected by the fungus. Satisfactory levels of control were achieved when the dew period was >20 h and temperature during the dew period was 30 C. Control of fireweed increased when the C. dematium f.sp. epilobii conidia were suspended in a 25% v/v canola oil/water emulsion. Using this formulation, control of 4-wk-old seedlings was obtained with a 10-fold reduction in inoculum concentration (1 × 108 conidia/m2), the required dew period was reduced to 12 h, and the effect of the temperature during the dew period was minimized. In the field, C. dematium f.sp. epilobii alone or when amended with an oil emulsion failed to control fireweed growth. When the oil formulation of C. dematium f.sp. epilobii was tank mixed with a low rate of glyphosate, high levels of control were consistently achieved. Growth reduction achieved with this formulation was more than additive, suggesting a synergistic interaction. The effectiveness of the formulated conidial suspension of C. dematium f.sp. epilobii decreased with plant maturity, and 15-wk-old plants were not controlled. C. dematium f.sp. epilobii alone has limited potential as a candidate bioherbicide, but when formulated in an oil/water emulsion and combined with low rates of glyphosate, suppression of fireweed can be attained in the field.
Contributors
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- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
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- The Cambridge Dictionary of Philosophy
- Published online:
- 05 August 2015
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- 27 April 2015, pp ix-xxx
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Effects of low protein diets on fat deposition in the whole body and within the muscle and subcutaneous adipose tissue of pigs
- G G Stonehouse, S I Hughes, K Hallett, A Stewart, J D Wood
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- Journal:
- Proceedings of the British Society of Animal Science / Volume 2009 / April 2009
- Published online by Cambridge University Press:
- 22 November 2017, p. 102
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- April 2009
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Protein is an expensive nutrient in pig diets and high protein diets lead to high N excretion, a source of pollution. Low protein nutritional strategies are therefore needed, but these often increase fat deposition. This study compared three nutritional strategies differing in protein and energy supply using genotypes with different propensities for fat deposition.
Effect of a low protein : energy nutritional strategy on intramuscular and subcutaneous fatty acid content, and stearoyl-CoA desaturase protein expression in Large White and Duroc pigs
- O Doran, G. G. Stonehouse, K. G. Hallett, J. D. Wood
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- Journal:
- Proceedings of the British Society of Animal Science / Volume 2008 / 2008
- Published online by Cambridge University Press:
- 23 November 2017, p. 253
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- 2008
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The production of pigs with low subcutaneous but high intramuscular fat (IMF) is one of the main challenges of the pig industry, and it requires the understanding of the mechanisms controlling fat formation in these two depots. IMF can be increased by reducing the ratio of protein to energy in pig diets (Wood et al.,, 2004). This is accompanied by activation of expression of the enzyme stearoyl-CoA-desaturase (SCD), which catalyses the biosynthesis of monounsaturated fatty acids (MUFA) (Doran et al., 2006). It is well known that IMF content varies between breeds. However it remains unclear as to whether pigs with predominantly high IMF (e.g. Duroc) will respond to a low protein diet in the same way as those with predominantly low IMF (e.g. Large White). The objective of the present study was to investigate whether the effects of low protein: energy diets on IMF, MUFA and total fatty acid content are breed-specific.
The fatty acid composition of muscle fat and relationships to meat quality in Charolais steers: influence of level of red clover in the diet
- N D Scollan, P Costa, K G Hallett, G R Nute, J D Wood, R I Richardson
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- Journal:
- Proceedings of the British Society of Animal Science / Volume 2006 / March 2006
- Published online by Cambridge University Press:
- 23 November 2017, p. 23
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- March 2006
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Legumes are important constituents of ruminant diets and are a vital part of low input and organic systems. Previous studies have established the high intake characteristics and animal production potential of red clover silage. Studies with milk produced from cows fed on red clover silage was noted to have higher levels of polyunsaturated fatty acids (PUFA) but had a reduced shelf life which could be ameliorated by feeding additional vitamin E (Al-Mabruk et al., 2004). This study considered the effects of incremental inclusion of red clover silage in the diet of beef cattle on the fatty acid composition of the m. longissimus dorsi and meat quality.
A reduced protein diet induces stearoyl-CoA desaturase protein expression in pig muscle but not in subcutaneous adipose tissue: relationship with intramuscular lipid formation
- O. Doran, S. K. Moule, G. A. Teye, F. M. Whittington, K. G. Hallett, J. D. Wood
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- Journal:
- British Journal of Nutrition / Volume 95 / Issue 3 / March 2006
- Published online by Cambridge University Press:
- 08 March 2007, pp. 609-617
- Print publication:
- March 2006
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A reduced protein diet (RPD) is known to increase the level of intramuscular lipid in pig meat with a smaller effect on the amount of subcutaneous adipose tissue. This might be due to tissue-specific activation of the expression of lipogenic enzymes by the RPD. The present study investigated the effect of a RPD, containing palm kernel oil, soyabean oil or palm oil on the activity and expression of one of the major lipogenic enzymes, stearoyl-CoA desaturase (SCD) and on the level of total lipids and the fatty acid composition of muscle and subcutaneous adipose tissue in pigs. The RPD significantly increased SCD protein expression and activity in muscle but not in subcutaneous adipose tissue. The level of MUFA and total fatty acids in muscle was also elevated when the RPD was fed, with only small changes in subcutaneous adipose tissue. A positive significant correlation between SCD protein expression and total fatty acids in muscle was found. The results suggest that an increase in intramuscular but not subcutaneous adipose tissue fatty acids under the influence of a RPD is related to tissue-specific activation of SCD expression. It is suggested that the SCD isoform spectra in pig subcutaneous adipose tissue and muscle might be different.
Biohydrogenation of n-3 polyunsaturated fatty acids in the rumen and their effects on microbial metabolism and plasma fatty acid concentrations in sheep
- L. A. Sinclair, S. L. Cooper, S. Chikunya, R. G. Wilkinson, K. G. Hallett, M. Enser, J. D. Wood
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- Journal:
- Animal Science / Volume 81 / Issue 2 / October 2005
- Published online by Cambridge University Press:
- 09 March 2007, pp. 239-248
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- October 2005
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Six cannulated wether sheep weighing 57 (s.d. 4·3) kg were used to investigate the susceptibility of unprotected and protected n-3 polyunsaturated fatty acids from different sources to biohydrogenation in the rumen, their uptake into plasma and effects on ruminal metabolism. The sheep were assigned to one of six dietary treatments formulated to have a similar fatty acid content (60 g/kg DM) and containing: linseed oil (LO), linseed oil absorbed into vermiculite (VLO), formic acid-formaldehyde treated whole linseed (FLS), fish oil (FO), fat encapsulated fish oil (PFO) or a mixture of fish oil and marine algae (1: 1 on an oil basis; AF), in six periods of 28 days duration in a Latin-square design. Biohydrogenation of C20:5 (n-3) and C22:6 (n-3) was high in FO at approximately 870 g/kg, but reduced to 625 and 625 g/kg respectively for PFO, and 769 and 601 g/kg respectively for AF. Ruminal biohydrogenation of C18:3 (n-3) was similar across treatments based on linseed, averaging 860 g/kg, but C18:2 (n-6) was lower (P < 0·05) in animals given VLO or FLS at 792 and 837 g/kg respectively, compared with LO (907 g/kg). Duodenal flow of C18:1 trans in animals given any of the diets containing fish oil averaged 8·4 g/day compared with 2·8 g/day in animals given diets based on linseed (P < 0·001), whilst cis-9, trans-11 conjugated linoleic acid was not significantly different among treatments. Plasma C20:5 (n-3) and C22:6 (n-3) proportions were highest in animals given the AF diet (11·8 and 8·2 g per 100 g of the total fatty acids respectively) and lowest in animals given LO (2·8 and 2·7 g per 100 g of the total fatty acids respectively; P < 0·001). By contrast, plasma C18:3 (n-3) proportions were highest in animals given the LO or VLO diets at approximately 6·9 g per 100 g of the total fatty acids, and lowest in the AF treatment at 0·9 g per 100 g (P < 0·001). Duodenal non-ammonia-N flow was similar among treatments at 21·0 g/day except in animals given FLS which had the highest flow (25·9 g N per day; P < 0·01). Microbial N flow was also similar among treatments whilst microbial efficiency (g N per kg OM truly degraded in the rumen) was higher (P < 0·05) in animals given FLS than LO, FO or AF. By contrast, ruminal fibre digestion was higher (P < 0·05) in animals given LO or FO than those offered VLO, FLS, PFO or AF. In conclusion, compared with linseed oil, absorption of linseed oil into vermiculite improved duodenal flow but not plasma levels of C18:3 (n-3), whilst formic acid-formaldehyde treatment of linseed had little effect on protecting C18:3 (n-3) in the rumen, although duodenal non-ammonia nitrogen flow and microbial efficiency were improved. Compared with fish oil, the provision of marine algae or fat encapsulated fish oil resulted in a lower biohydrogenation of C22:6 (n-3) and C20:5 (n-3), and an increased duodenal flow and plasma concentration and offers the potential to favourably manipulate the n-3 fatty acid composition of sheep meat.
Fatty acid composition and quality of muscle from steers fed ruminally protected lipid
- M. Enser, N. Scollan, S. Gulati, G. Nute, K. Hallett, J.D. Wood, I Richardson
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- Journal:
- Proceedings of the British Society of Animal Science / Volume 2002 / 2002
- Published online by Cambridge University Press:
- 20 November 2017, p. 178
- Print publication:
- 2002
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Recommendations to improve the UK diet suggest an increase in the ratio of polyunsaturated to saturated fatty acids (P:S ratio) and a higher consumption of n-3 polyunsaturated fatty acids (PUFA). Ruminant meats have a poor P:S ratio, approximately 0.1 compared to the recommendation of 0.4-1.0 for the whole diet. However, the ratio of C18:2 n-6/C18:3 n-3 (the n-6:n-3) is well within the recommended value of <4.0 at approximately 2 and ruminant muscle also supplies longer-chain n-3 PUFA. By feeding lipid in a formaldehyde cross-linked protein matrix, rumen biohydrogenation can be avoided and the tissue PUFA level increased but with potential effects on oxidative shelf-life, colour and flavour of the meat. This trial investigated the fatty acid composition and quality of meat produced by feeding a protected lipid supplement (PLS).
Rumen biohydrogenation of n-3 polyunsaturated fatty acids and their effects on microbial efficiency and nutrient digestibility in sheep
- A. M. WACHIRA, L. A. SINCLAIR, R. G. WILKINSON, K. HALLETT, M. ENSER, J. D. WOOD
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- Journal:
- The Journal of Agricultural Science / Volume 135 / Issue 4 / December 2000
- Published online by Cambridge University Press:
- 23 January 2001, pp. 419-428
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The study examined the extent to which n-3 PUFA from different sources were biohydrogenated in the rumen and their effects on rumen microbial efficiency and whole tract nutrient digestibility. Four ruminally and duodenally cannulated wether lambs were used in a 4×4 Latin square design. Four iso-energetic and iso-nitrogenous diets based on dried grass were formulated to provide similar fat levels (60g/kg DM) from different sources; Megalac (palmitic acid: C16:0; Control), whole linseed (α-linolenic acid, C18:3n-3 ; Linseed) fish oil (eicosapentaenoic acid, C20:5n-3, EPA and docosahexaenoic acids C22:6n-3, DHA; Fish oil) and whole linseed plus fish oil providing equal amounts of oil (LinFish). Diets were offered at a rate of 1·2kg/day in 12 equal portions.
Total fatty acid intake was similar on all diets whilst duodenal fatty acid flow varied between 101, 94, 87 and 90% of dietary intake for animals fed the Control, Linseed, Fish oil and Linfish diets respectively. Duodenal flow of C18:3 n-3 in animals fed the Linseed diet was twice that of animals fed the Control diet (P < 0·01) whilst animals fed the Fish oil diet had a significantly greater flow of EPA and DHA than those fed any of the other dietary treatments. Duodenal flow of trans C18:1 in animals fed the Linfish diet was significantly greater than that in animals fed either Linseed, Fish oil or Control diets (P < 0·001). Biohydrogenation of C18:3n-3 was 80 to 93% in all diets whilst that of C20:5n-3 and C22:6n-3 was 72 to 79% in diets that contained fish oil or linseed and fish oil. Apparent fatty acid digestibility (duodenum to rectum) tended to be greater for unsaturated than saturated fatty acids whilst whole tract fatty acid digestibility (mouth to rectum) was significantly greater in animals fed diets containing fish oil (P0·05). All dietary n-3 PUFA sources decreased microbial protein synthesis and efficiency when expressed as either gN/kg organic matter (OM) apparently or truly degraded in the rumen. Additionally, the inclusion of fish oil increased the proportion of propionate in the rumen whilst depressing the rumen digestibility of OM and fibre (P < 0·01), but had no significant effect on whole tract OM or fibre digestibility.
Eating quality of lamb: differences between extreme breed x production system groups
- G. R. Nute, J. D. Wood, M. Enser, K. G. Hallett, L.A. Sinclair, R. G. Wilkinson
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- Journal:
- Proceedings of the British Society of Animal Science / Volume 1999 / 1999
- Published online by Cambridge University Press:
- 20 November 2017, p. 116
- Print publication:
- 1999
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There is anecdotal evidence that certain sheep breeds, reared in a particular way, produce unusual or characteristic tastes in cooked meat. Such effects could be linked to differences in meat fatty acid composition associated with the consumption of different diets. This study investigated eating quality and fat composition in 4 distinctively different breed x feeding system groups.
Four groups of 20 ram lambs were obtained as follows: Pure Soays (SO) finished off grass in April from commercial breeders; Pure Welsh Mountain (WM) finished off upland grass in October from ADAS Pwllpeiran; Suffolk x Mules from Harper Adams College finished off concentrates (grains) (SC) in April; and Suffolk x mules from the same source finished off grass (SG) in May. The animals were transported to Langford where they were slaughtered in Bristol University's abattoir.