Mr John Tweed

Mr John Tweed

Research Scientist

Contact Details

Publications

Use of near-infrared reflectance spectroscopy to predict individual and total fatty acid content of perennial ryegrass (Lolium perenne)Morgan, S., Huws, S., Tweed, J., Sanderson, R., Lister, S. & Scollan, N. 2016 p. 55
Use Of Fourier-Transform Infrared Spectroscopy To Predict Forage Ryegrass Fatty Acid CompositionMoorby, J., Palmer, S., Lovatt, J., Scott, M., Morgan, S. & Tweed, J. 2015 Proceedings of the Twelfth BGS Research Conference. Moorby, J. & Jewkes, E. (eds.). British Grassland Society, p. 69-70
Seasonal variability in the relationship between fatty acid and chlorophyll content of perennial ryegrass (lolium perenne)Morgan, S., Huws, S., Tweed, J. & Scollan, N. 2015 p. 107
Characterization of the rumen lipidome and microbiome of steers fed a diet supplemented with flax and echium oilHuws, S., Kim, E. J., Cameron, S. J., Girdwood, S. E., Davies, L. J., Tweed, J., Vallin, H. E. & Scollan, N. 2015 In : Microbial Biotechnology.8, 2, p. 331-34121 p.
Relationship between fatty acid content and nutritive value of perennial ryegrass (lolium perenne)Morgan, S., Huws, S., Tweed, J., Hayes, R. & Scollan, N. 2014 p. 550-552
Characterising the fatty acid profile of beef supplied through a premium Welsh beef supply-chainMorgan, S., Huws, S., Tweed, J., Evans, G. H., Rowe, T. D. M. & Scollan, N. 2014 p. 164
Fatty acid oxidation products (‘green odour’) released from perennial ryegrass following biotic and abiotic stress, potentially have antimicrobial properties against the rumen microbiota resulting in decreased biohydrogenationHuws, S. A., Scott, M. B., Tweed, J. K. S. & Lee, M. R. F. 2013 In : Journal of Applied Microbiology.115, 5, p. 1081-1090
Relationship between chlorophyll content (a+b) (SPAD values) and fatty acid composition of perennial ryegrass (lolium perenne)Morgan, S., Huws, S., Tweed, J., Hayes, R. & Scollan, N. 2013 p. 146
Ruminal protozoal contribution to the duodenal flow of fatty acids following feeding of steers on forages differing in chloroplast contentHuws, S. A., Lee, M. R. F., Kingston-Smith, A. H., Kim, E. J., Scott, M. B., Tweed, J. K. S. & Scollan, N. D. 2012 In : British Journal of Nutrition.108, 12, p. 2207-2214
Beef, chicken and lamb fatty acid anlysis - a simplified direct bimethylation procedure using freeze-dried materialLee, M. R. F., Tweed, J. K. S., Kim, E. J. & Scollan, N. D. 2012 In : Meat Science.92, 4, p. 863-8664 p.
Oxidation of ortho-diphenols in red clover with and without polyphenol oxidase (PPO) activity and their role in PPO activation and inactivationLee, M. R. F., Tweed, J. K. S. & Sullivan, M. L. 2012 In : Grass and Forage Science.68, 1, p. 83-929 p.
As yet uncultured bacteria phylogenetically classified as Prevotella, Lachnospiraceae incertae sedis and unclassified Bacteroidales, Clostridiales and Ruminococcaceae may play a predominant role in ruminal biohydrogenationHuws, S. A., Kim, E. J., Lee, M. R., Scott, M. B., Tweed, J. K., Pinloche, E., Wallace, R. J. & Scollan, N. D. 2011 In : Environmental Microbiology.13, 6, p. 1500-151213 p.
Auto-oxidation of orthodiphenolic substrate and deactivation of polyphenol oxidases (catecholase) during wilting and post harvest damage in red cloverLee, M. R. F., Tweed, J. K. S. & Sullivan, M. L. 2011 p. p. 280280 p.
The influence of grass silages with contrasting polyphenol oxidase activity versus red clover on rumen ammonia and the flow of amino acids to the duodenum in beef steersLee, M. R. F., Gordon, N., Tweed, J. K. S., Theobald, V. J., Fychan, A. R. & Scollan, N. D. 2011 Eighth International Symposium for the Nutrition of Herbivores, Aberystwyth..Unknown Publisher, p. 427-4271 p.
The potential of grass silage with contrating polyphenol oxidase activity versus red clover to protect C18 polyunsaturated fatty acid across the rumen of beef steersLee, M. R., Gordon, N., Tweed, J., Theobald, V., Fychan, A. & Scollan, N. 2011 p. 4261 p.
The influence of plant polyphenols on lipolysis and biohydrogenation in dried forages at different phenological stages in vitroCabiddu, A., Sallis, L., Tweed, J. K. S., Molle, G., Decandia, M. & Lee, M. R. F. 2010 In : Journal of the Science of Food and Agriculture.90, 5, p. 829-8357 p.
Immunogold labelling to localize polyphenol oxidase (PPO) during wilting of red clover leaf tissue and the effect of removing cellular matrices on PPO protection of glycerol-based lipid in the rumenLee, M. R. F., Tweed, J. K. S., Cookson, A. & Sullivan, M. L. 2010 In : Journal of the Science of Food and Agriculture.90, 3, p. 503-5108 p.
Contribution of ruminal protozoa to the duodenal flow of polyunsaturated fatty acids following feeding on low and high chloroplastsHuws, S. A., Kingston-Smith, A. H., Kim, E. J., Lee, M. R. F., Scott, M. B., Tweed, J. K. S. & Scollan, N. D. 2010 p. p 53
Effects of fatty acid oxidation products ('green odour') on rumen bacterial populations and lipid metabolism in vitroHuws, S. A., Scott, M. B., Tweed, J. K. S. & Lee, M. R. F. 2010 p. 50
As yet uncultured bacteria may play a predominant role in ruminal biohydrogenationHuws, S. A., Kim, E. J., Lee, M. R. F., Scott, M. B., Tweed, J. K. S., Pinloche, E., Wallace, R. J. & Scollan, N. D. 2010 p. p 52
Yucca shidigera extracted saponin cause shifts in the rumen microbiota alongside decreased lipolysis and biohydrogenationHuws, S. A., Lee, M. R. F., Tweed, J. K. S., Scott, M. B. & Scollan, N. D. 2010 p. p 51
Effects of fatty acid oxidation products (‘green odour’) on rumen bacterial populations and lipid metabolism in vitro.Huws, S. A., Scott, M. B., Tweed, J. K. . S. & Lee, M. R. F. 2010
Contribution of ruminal protozoa to the duodenal flow of polyunsaturated fatty acids as a consequence of intracellular chloroplasts.Huws, S. A., Kingston-Smith, A. H., Kim, E. J., Lee, M. R. F., Scott, M. B., Tweed, J. K. S. & Scollan, N. D. 2010
Saponins extracted from Yucca shidigera cause shifts in the rumen microbiota resulting in decreased lipolysis and biohydrogenation.Huws, S. A., Lee, M. R. F., Tweed, J. K. S., Scott, M. B. & Scollan, N. D. 2010
Red clover polyphenol oxidase: activation activity and efficacy under grazingLee, M. R. F., Tweed, J. K. S., Minchin, F. R. & Winters, A. L. 2009 In : Animal Feed Science and Technology.149, 3-4, p. 250-26415 p.
Effect of feeding fresh or conditioned red clover on milk fatty acids and Nitrogen utilisation in lactating dairy cowsLee, M. R. F., Theobald, V. J., Tweed, J. K. S., Winters, A. L. & Scollan, N. D. 2009 In : Journal of Dairy Science.92, 3, p. 1136-114712 p.
Isomerisation of trans-10 cis-12 conjugated linoleic acid during acidic methylationLee, M. R. F. & Tweed, J. K. S. 2009 p. 146146 p.
Effect of fish oil on ruminal biohydrogenation of C18 unsaturated fatty acids in steers fed grass or red clover silagesLee, M. R. F., Shingfield, K. J., Tweed, J. K. S., Toivonen, V., Huws, S. A. & Scollan, N. D. 2008 In : Animal.2, 12, p. 1859-186911 p.
Ruminal micro-organisms do not adapt to increase utilization of poly-phenol oxidase protected red clover protein and glycerol-based lipidLee, M. R. F., Tweed, J. K. S., Scollan, N. D. & Sullivan, M. L. 2008 In : Journal of the Science of Food and Agriculture.88, 14, p. 2479-24857 p.
Isomerisation of cis-9 trans-11 conjugated linoleic acid (CLA) to trans-9 trans-11 CLA during acidic methylation can be avoided by a rapid base catalysed methylation of milk fatLee, M. R. F. & Tweed, J. K. S. 2008 In : Journal of Dairy Research.75, 3, p. 354-3563 p.
Effects of polyphenol oxidase on lipolysis and proteolysis of red clover silage with and without a silage inoculant (Lactobacillus plantarum L54)Lee, M. R. F., Scott, M. B., Tweed, J. K. S., Minchin, F. R. & Davies, D. R. 2008 In : Animal Feed Science and Technology.144, 1-2, p. 125-13612 p.
Milk C18:1 and conjugated linoleic acid isomers from cows grazed on perennial ryegrass, tall fescue or timothy swardsEllis, N. M., Kim, E. J., Lee, M. R. F., Scollan, N. D., Tweed, J. K. S. & Gordon, N. M. 2008 21st International Grassland Congress and the International Rangeland Congress on 29th June - 5th July, 2008 in Hohhot, China..p. p659
Milk C18 polyunsaturated fatty acids from cows grazed on perennial ryegrass, tall fescue or timothy swardsLee, M. R. F., Ellis, N., Kim, E. J., Tweed, J. K. S., Scollan, N. D. & Gordon, N. M. 2008 21st International Grassland Congress.p. p658
Mechanism of polyphenol oxidase action in reducing lipolysis and proteolysis in red clover during batch cultureLee, M. R. F., Tweed, J. K. S., Scollan, N. D. & Sullivan, M. L. 2008 p. p031
Effects of high-sugar ryegrass silage and mixtures with red clover silage on ruminant digestion. 2. LipidsLee, M. R. F., Connelly, P. L., Tweed, J. K. S., Dewhurst, R. J., Merry, R. J. & Scollan, N. D. 2006 In : Journal of Animal Science.84, 11, p. 3061-307010 p.
Effect of forage: concentrate ratio on ruminal metabolism and duodenal flow of fatty acids in beef steersLee, M. R. F., Tweed, J. K. S., Dewhurst, R. J. & Scollan, N. D. 2006 In : Animal Science.82, 1, p. 31-4010 p.
The effect of fish oil supplementation on rumen metabolism and the biohydrogenation of unsaturated fatty acids in beef steers given diets containing sunflower oilLee, M. R. F., Tweed, J. K. S., Moloney, A. P. & Scollan, N. D. 2005 In : Animal Science.80, 3, p. 361-3677 p.
An in vitro investigation of forage factors which affect the production of conjugated linoleic acid and trans vaccenic acid in the rumen. II. Wilting & cell damageLee, M. R. F., Tweed, J. K. S., Scollan, N. D. & Dewhurst, R. J. 2005 XX International Grassland Conference: Offered papers. O'Mara, F. P., Wilkins, R. J., 't Mannetje, L., Lovett, D. K., Rogers, P. A. M. & Boland, T. M. (eds.). Wageningen Academic Publishers, p. p180 (XX International Grassland Congress)
An in vitro investigation of forage factors which affect the production of conjugated linoleic acid and trans vaccenic acid in the rumen. I. Grass speciesLee, M. R. F., Hodgkins, C., Tweed, J. K. S., Scollan, N. D. & Dewhurst, R. J. 2005 XX International Grassland Conference: Offered papers. O'Mara, F. P., Wilkins, R. J., 't Mannetje, L., Lovett, D. K., Rogers, P. A. M. & Boland, T. M. (eds.). Wageningen Academic Publishers, (XX International Grassland Congress)
Duodenal flow of the chlorophyll metabolite phytanic acid in beef steers offered grass and red cloverLee, M. R. F., Tweed, J. K. S., Dewhurst, R. J. & Scollan, N. D. 2004 Plants as animal foods: a case of Catch 22?.The Nutrition Society
Comparison of grass and legume silages for milk production: 1. Production responses with different levels of concentrateDewhurst, R. J., Fisher, W. J., Tweed, J. K. S. & Wilkins, R. J. 2003 In : Journal of Dairy Science.p. 2598-261114 p.
Effects of a stay-green trait on the concentrations and stability of fatty acids in perennial ryegrassDewhurst, R. J., Moorby, J. M., Scollan, N. D., Tweed, J. K. S. & Humphreys, M. O. 2002 In : Grass and Forage Science.p. 360-3667 p.
Effects of legume silages on the concentration of alpha-linolenic acid in milkDavies, D. W. R., Tweed, J. K. S., Dewhurst, R. J., Fisher, W. J., Gechie, L. M. (ed.) & Thomas, C. (ed.) 2002 p. 11-133 p.
Effect of ensiling on the fatty acid composition of the resultant silageWarren, H. E., Tweed, J. K. S., Youell, S. J., Dewhurst, R. J., Lee, M. R. F. & Scollan, N. D. 2002 Multi-Function Grasslands: Quality Forages, Animal Products and Landscapes. Durand, J-L., Emile, J-C., Huyghe, C. & Lemaire, G. (eds.). European Grassland Federation, p. 1001-1011 p. (Grassland Science in Europe; vol. 7)
Influence of species, cutting date and cutting interval on the fatty acid composition of grassesDewhurst, R. J., Scollan, N. D., Youell, S. J., Tweed, J. K. S. & Humphreys, M. O. 2001 In : Grass and Forage Science.56, 1, p. 68-747 p.
Effects of Altering the Energy and Protein Supply to Dairy Cows During the Dry Period. 2. Metabolic and Hormonal ResponsesMoorby, J., Dewhurst, R. J., Tweed, J., Dhanoa, M. S. & Beck, N. 2000 In : Journal of Dairy Science.83, 8, p. 1795-1805
Proteolysis During Ensilage of Forages Varying in Soluble Sugar ContentDavies, D. R., Merry, R. J., Williams, A. P., Bakewell, E. L., Leemans, D. & Tweed, J. 1998 In : Journal of Dairy Science.81, 2, p. 444-453