Mr John Tweed

Mr John Tweed

Research Scientist

Contact Details

Publications

2016

Morgan, S., Huws, S., Tweed, J., Sanderson, R., Lister, S., Scollan, N. 2016. Use of near-infrared reflectance spectroscopy to predict individual and total fatty acid content of perennial ryegrass (Lolium perenne). Proceedings of the British Society of Animal Science in association with AHDB; 'Animal Science for a Sustainable Future'. Cadair

2015

Moorby, J., Palmer, S., Lovatt, J., Scott, M., Morgan, S., Tweed, J. 2015. Use Of Fourier-Transform Infrared Spectroscopy To Predict Forage Ryegrass Fatty Acid Composition. In J. Moorby., E. Jewkes. (eds) Proceedings of the Twelfth BGS Research Conference. 12th British Grassland Society Conference. British Grassland Society pp. 69-70. Cadair

Morgan, S., Huws, S., Tweed, J., Scollan, N. 2015. Seasonal variability in the relationship between fatty acid and chlorophyll content of perennial ryegrass (lolium perenne). Proceedings of the British Society of Animal Science in association with AVTRW, CFER and EBLEX; 'Science with Impact'. Cadair

Huws, S., Kim, E.J., Cameron, S.J., Girdwood, S.E., Davies, L.J., Tweed, J., Vallin, H.E., Scollan, N. 2015. Characterization of the rumen lipidome and microbiome of steers fed a diet supplemented with flax and echium oil. Microbial Biotechnology 8 (2) pp. 331-341. 10.1111/1751-7915.12164 Cadair

2014

Morgan, S., Huws, S., Tweed, J., Hayes, R., Scollan, N. 2014. Relationship between fatty acid content and nutritive value of perennial ryegrass (lolium perenne). Proceedings of the 25th General Meeting of the European Grassland Federation. Cadair

Morgan, S., Huws, S., Tweed, J., Evans, G.H., Rowe, T.D.M., Scollan, N. 2014. Characterising the fatty acid profile of beef supplied through a premium Welsh beef supply-chain. Proceedings of the British Society of Animal Science and the AVTRW includes BSAS/EBLEX Workshop Improving Ewe Efficiency Through Better Feeding; 'Science into Practice: Planning for Intensification'. Cadair

2013

Huws, S.A., Scott, M.B., Tweed, J.K.S., Lee, M.R.F. 2013. 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 biohydrogenation. Journal of Applied Microbiology 115 (5) pp. 1081-1090. 10.1111/jam.12314 Cadair

Morgan, S., Huws, S., Tweed, J., Hayes, R., Scollan, N. 2013. Relationship between chlorophyll content (a+b) (SPAD values) and fatty acid composition of perennial ryegrass (lolium perenne). Proceedings of the British Society of Animal Science and the AVTRW includes papers from the RBST 40th Anniversary Seminar and the CFER; 'Innovation from Animal Science - a necessity not an option'. Cadair

2012

Huws, S.A., Lee, M.R.F., Kingston-Smith, A.H., Kim, E.J., Scott, M.B., Tweed, J.K.S., Scollan, N.D. 2012. Ruminal protozoal contribution to the duodenal flow of fatty acids following feeding of steers on forages differing in chloroplast content. British Journal of Nutrition 108 (12) pp. 2207-2214. 10.1017/S0007114512000335 Cadair

Lee, M.R.F., Tweed, J.K.S., Kim, E.J., Scollan, N.D. 2012. Beef, chicken and lamb fatty acid anlysis - a simplified direct bimethylation procedure using freeze-dried material. Meat Science 92 (4) pp. 863-866. 10.1016/j.meatsci.2012.06.013 Cadair

Lee, M.R.F., Tweed, J.K.S., Sullivan, M.L. 2012. Oxidation of ortho-diphenols in red clover with and without polyphenol oxidase (PPO) activity and their role in PPO activation and inactivation. Grass and Forage Science 68 (1) pp. 83-92. 10.1111/j.1365-2494.2012.00873.x Cadair

2011

Huws, S.A., Kim, E.J., Lee, M.R., Scott, M.B., Tweed, J.K., Pinloche, E., Wallace, R.J., Scollan, N.D. 2011. As yet uncultured bacteria phylogenetically classified as Prevotella, Lachnospiraceae incertae sedis and unclassified Bacteroidales, Clostridiales and Ruminococcaceae may play a predominant role in ruminal biohydrogenation. Environmental Microbiology 13 (6) pp. 1500-1512. 10.1111/j.1462-2920.2011.02452.x Cadair

Lee, M.R.F., Tweed, J.K.S., Sullivan, M.L. 2011. Auto-oxidation of orthodiphenolic substrate and deactivation of polyphenol oxidases (catecholase) during wilting and post harvest damage in red clover. Cadair

Lee, M.R.F., Gordon, N., Tweed, J.K.S., Theobald, V.J., Fychan, A.R., Scollan, N.D. 2011. 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 steers. Eighth International Symposium for the Nutrition of Herbivores, Aberystwyth. 8th International Symposium for the Nutrition of Herbivores. Unknown Publisher pp. 427-427. Cadair

Lee, M.R., Gordon, N., Tweed, J., Theobald, V., Fychan, A., Scollan, N. 2011. The potential of grass silage with contrating polyphenol oxidase activity versus red clover to protect C18 polyunsaturated fatty acid across the rumen of beef steers. Eighth International Symposium for the Nutrition of Herbivores (ISNH8). Cadair

2010

Cabiddu, A., Sallis, L., Tweed, J.K.S., Molle, G., Decandia, M., Lee, M.R.F. 2010. The influence of plant polyphenols on lipolysis and biohydrogenation in dried forages at different phenological stages in vitro. Journal of the Science of Food and Agriculture 90 (5) pp. 829-835. 10.1002/jsfa.3892 Cadair

Lee, M.R.F., Tweed, J.K.S., Cookson, A., Sullivan, M.L. 2010. 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 rumen. Journal of the Science of Food and Agriculture 90 (3) pp. 503-510. 10.1002/jsfa.3848 Cadair

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. Contribution of ruminal protozoa to the duodenal flow of polyunsaturated fatty acids following feeding on low and high chloroplasts. ProSafeBeef Annual General Meeting - EU Framework 6. Cadair

Huws, S.A., Scott, M.B., Tweed, J.K.S., Lee, M.R.F. 2010. Effects of fatty acid oxidation products ('green odour') on rumen bacterial populations and lipid metabolism in vitro. ProSafeBeef Annual General Meeting - EU Framework 6. Cadair

Huws, 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. As yet uncultured bacteria may play a predominant role in ruminal biohydrogenation. ProSafeBeef Annual General Meeting - EU Framework 6. Cadair

Huws, S.A., Lee, M.R.F., Tweed, J.K.S., Scott, M.B., Scollan, N.D. 2010. Yucca shidigera extracted saponin cause shifts in the rumen microbiota alongside decreased lipolysis and biohydrogenation. ProSafeBeef Annual General Meeting - EU Framework 6. Cadair

Huws, S.A., Scott, M.B., Tweed, J.K./.S., Lee, M.R.F. 2010. Effects of fatty acid oxidation products (‘green odour’) on rumen bacterial populations and lipid metabolism in vitro. Cadair

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. Contribution of ruminal protozoa to the duodenal flow of polyunsaturated fatty acids as a consequence of intracellular chloroplasts. Cadair

Huws, S.A., Lee, M.R.F., Tweed, J.K.S., Scott, M.B., Scollan, N.D. 2010. Saponins extracted from Yucca shidigera cause shifts in the rumen microbiota resulting in decreased lipolysis and biohydrogenation. Cadair

2009

Lee, M.R.F., Tweed, J.K.S., Minchin, F.R., Winters, A.L. 2009. Red clover polyphenol oxidase: activation activity and efficacy under grazing. Animal Feed Science and Technology 149 (3-4) pp. 250-264. 10.1016/j.anifeedsci.2008.06.013 Cadair

Lee, M.R.F., Theobald, V.J., Tweed, J.K.S., Winters, A.L., Scollan, N.D. 2009. Effect of feeding fresh or conditioned red clover on milk fatty acids and Nitrogen utilisation in lactating dairy cows. Journal of Dairy Science 92 (3) pp. 1136-1147. 10.3168/jds.2008-1692 Cadair

Lee, M.R.F., Tweed, J.K.S. 2009. Isomerisation of trans-10 cis-12 conjugated linoleic acid during acidic methylation. Other Cadair

2008

Lee, M.R.F., Shingfield, K.J., Tweed, J.K.S., Toivonen, V., Huws, S.A., Scollan, N.D. 2008. Effect of fish oil on ruminal biohydrogenation of C18 unsaturated fatty acids in steers fed grass or red clover silages. Animal 2 (12) pp. 1859-1869. 10.1017/S1751731108002899 Cadair

Lee, M.R.F., Tweed, J.K.S., Scollan, N.D., Sullivan, M.L. 2008. Ruminal micro-organisms do not adapt to increase utilization of poly-phenol oxidase protected red clover protein and glycerol-based lipid. Journal of the Science of Food and Agriculture 88 (14) pp. 2479-2485. 10.1002/jsfa.3366 Cadair

Lee, M.R.F., Tweed, J.K.S. 2008. 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 fat. Journal of Dairy Research 75 (3) pp. 354-356. 10.1017/S0022029908003518 Cadair

Lee, M.R.F., Scott, M.B., Tweed, J.K.S., Minchin, F.R., Davies, D.R. 2008. Effects of polyphenol oxidase on lipolysis and proteolysis of red clover silage with and without a silage inoculant (Lactobacillus plantarum L54). Animal Feed Science and Technology 144 (1-2) pp. 125-136. 10.1016/j.anifeedsci.2007.09.035 Cadair

Ellis, N.M., Kim, E.J., Lee, M.R.F., Scollan, N.D., Tweed, J.K.S., Gordon, N.M. 2008. Milk C18:1 and conjugated linoleic acid isomers from cows grazed on perennial ryegrass, tall fescue or timothy swards. 21st International Grassland Congress and the International Rangeland Congress on 29th June - 5th July, 2008 in Hohhot, China. 21st International Grassland Congress/International Rangeland Congress (IGC/IRC). pp. p659. Cadair Other

Lee, M.R.F., Ellis, N., Kim, E.J., Tweed, J.K.S., Scollan, N.D., Gordon, N.M. 2008. Milk C18 polyunsaturated fatty acids from cows grazed on perennial ryegrass, tall fescue or timothy swards. 21st International Grassland Congress. 21st International Grassland Congress/International Rangeland Congress (IGC/IRC). pp. p658. Cadair

Lee, M.R.F., Tweed, J.K.S., Scollan, N.D., Sullivan, M.L. 2008. Mechanism of polyphenol oxidase action in reducing lipolysis and proteolysis in red clover during batch culture. Proceedings of the British Society of Animal Science Annual Conference. Other Cadair

2006

Lee, M.R.F., Connelly, P.L., Tweed, J.K.S., Dewhurst, R.J., Merry, R.J., Scollan, N.D. 2006. Effects of high-sugar ryegrass silage and mixtures with red clover silage on ruminant digestion. 2. Lipids. Journal of Animal Science 84 (11) pp. 3061-3070. 10.2527/jas.2005-736 Cadair

Lee, M.R.F., Tweed, J.K.S., Dewhurst, R.J., Scollan, N.D. 2006. Effect of forage: concentrate ratio on ruminal metabolism and duodenal flow of fatty acids in beef steers. Animal Science 82 (1) pp. 31-40. 10.1079/ASC20058 Cadair

2005

Lee, M.R.F., Tweed, J.K.S., Moloney, A.P., Scollan, N.D. 2005. The effect 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 (3) pp. 361-367. 10.1079/ASC41920361 Cadair Other

Lee, M.R.F., Tweed, J.K.S., Scollan, N.D., Dewhurst, R.J. 2005. 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 damage. In F. P. O'Mara., R. J. Wilkins., L. 't Mannetje., D. K. Lovett., P. A. M. Rogers., T. M. Boland. (eds) XX International Grassland Conference: Offered papers. XX International Grassland Congress Wageningen Academic Publishers pp. p180. Cadair Other

Lee, M.R.F., Hodgkins, C., Tweed, J.K.S., Scollan, N.D., Dewhurst, R.J. 2005. An in vitro investigation of forage factors which affect the production of conjugated linoleic acid and trans vaccenic acid in the rumen. I. Grass species. In F. P. O'Mara., R. J. Wilkins., L. 't Mannetje., D. K. Lovett., P. A. M. Rogers., T. M. Boland. (eds) XX International Grassland Conference: Offered papers. XX International Grassland Congress Wageningen Academic Publishers Cadair Other

2004

Lee, M.R.F., Tweed, J.K.S., Dewhurst, R.J., Scollan, N.D. 2004. Duodenal flow of the chlorophyll metabolite phytanic acid in beef steers offered grass and red clover. Plants as animal foods: a case of Catch 22? Nutrition Society Meeting. The Nutrition Society Cadair

2003

Dewhurst, R.J., Fisher, W.J., Tweed, J.K.S., Wilkins, R.J. 2003. Comparison of grass and legume silages for milk production: 1. Production responses with different levels of concentrate. Journal of Dairy Science pp. 2598-2611. 10.3168/jds.S0022-0302(03)73855-7 Cadair Other

2002

Dewhurst, R.J., Moorby, J.M., Scollan, N.D., Tweed, J.K.S., Humphreys, M.O. 2002. Effects of a stay-green trait on the concentrations and stability of fatty acids in perennial ryegrass. Grass and Forage Science pp. 360-366. 10.1046/j.1365-2494.2002.00336.x Cadair

Davies, D.W.R., Tweed, J.K.S., Dewhurst, R.J., Fisher, W.J.Gechie, L.M., Thomas, C. 2002. Effects of legume silages on the concentration of alpha-linolenic acid in milk. Cadair

Warren, H.E., Tweed, J.K.S., Youell, S.J., Dewhurst, R.J., Lee, M.R.F., Scollan, N.D. 2002. Effect of ensiling on the fatty acid composition of the resultant silage. In J. Durand., J. Emile., C. Huyghe., G. Lemaire. (eds) Multi-Function Grasslands: Quality Forages, Animal Products and Landscapes. Grassland Science in Europe, vol. 7 Proceedings of the 19th General Meeting of the European Grassland Federation (EGF). European Grassland Federation pp. 1001-101. Cadair Other

2001

Dewhurst, R.J., Scollan, N.D., Youell, S.J., Tweed, J.K.S., Humphreys, M.O. 2001. Influence of species, cutting date and cutting interval on the fatty acid composition of grasses. Grass and Forage Science 56 (1) pp. 68-74. 10.1046/j.1365-2494.2001.00247.x Cadair

2000

Moorby, J., Dewhurst, R.J., Tweed, J., Dhanoa, M.S., Beck, N. 2000. Effects of Altering the Energy and Protein Supply to Dairy Cows During the Dry Period. 2. Metabolic and Hormonal Responses. Journal of Dairy Science 83 (8) pp. 1795-1805. 10.3168/jds.S0022-0302(00)75050-8 Cadair

1998

Davies, D.R., Merry, R.J., Williams, A.P., Bakewell, E.L., Leemans, D., Tweed, J. 1998. Proteolysis During Ensilage of Forages Varying in Soluble Sugar Content. Journal of Dairy Science 81 (2) pp. 444-453. 10.3168/jds.S0022-0302(98)75596-1 Cadair