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The University of Aberdeen
Rowett Institute of Nutrition and Health
University of Aberdeen
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Prof John Wallace obtained a 1st class Honours B.Sc. in Biochemistry from the University of Glasgow in 1972. Vacation placements included spells at the Forth River Purification Board and Distillers Company Ltd. Shortly after completing his Ph.D. at the University of Glasgow in 1975 ‘Maintenance energy and molar growth yields of Escherichia coli’, he joined the Microbiology Department of the Rowett Research institute, at that time headed by P.N. Hobson, with Sir Kenneth Blaxter as Institute Director. He has remained at the Rowett since 1976, developing interests in rumen and intestinal microbiology and ruminant nutrition. Following the merger of the Rowett with the University of Aberdeen in 2008, he was appointed to a Personal Chair at the University. He presently leads the rumen microbiology research team. At various times during his career, he has undertaken research sojourns in Australia, Japan and Ethiopia, and has served on the Editorial Boards of Microbiology, British Journal of Nutrition (Deputy Editor-in-Chief), FEMS Microbiology Letters, Animal Feed Science and Technology and Applied and Environmental Microbiology. He has served on the research committees of BBSRC and presently sit on the FEEDAP (feed additives) panel of the European Food Safety Authority. Career highlights include being invited to speak at the Pasteur Institute, Papeete, Tahiti, in ‘The Year of Louis Pasteur’ Symposium’, Microbes, Environment , Biotechnology, 8-12 May 1995, and being recognised via the DSM Nutrition Innovation Award in 2007 'in recognition of his pioneering research in animal nutrition.'
Research interests encompass microbial physiology, biochemistry and ecology that govern gut function, particularly in ruminants. Aspects of gut function of particular interest include: protein metabolism – which leads to inefficient protein retention by ruminants and the formation of toxic products in the human intestine; fatty acid biohydrogenation – which causes ruminant products to be low in most health-promoting PUFA; methane formation – a significant contributor to climate change; and ruminal acidosis – a major welfare issue for ruminants. Coupled with these issues are means by which manipulation of ruminal fermentation can be achieved, such as probiotics, phytochemicals and antimicrobials.
Methane is a greenhouse gas (GHG), 25 times as potent as carbon dioxide. Ruminants are major methane emitters, contributing 3-4% of global GHG emissions. The methane is derived from microbial fermentation in the rumen, being produced by microbes known as archaea. The archaea convert hydrogen and carbon dioxide produced by bacteria and protozoa to methane. In our Theme 5 work funded by RESAS, properties associated with methane emissions are being characterized, in collaboration with Bob Mayes of the James Hutton Institute and Rainer Roehe and John Rooke of the Scotland’s Rural College (SRUC), Edinburgh. We have established that the abundance of the archaea in ruminal digesta can be used to predict methane emissions of beef cattle, even using post-mortem samples. We have also identified some genetic traits governing methane emissions, and have characterised the methanogenic archaeal community in Scottish cattle, sheep and red deer. The Framework 7 project which I coordinate, ‘RuminOmics’ involves 11 European partners. The aims of the project are similar to the RESAS-funded work, but on a much larger scale, using unprecedentedly large animal cohorts in the UK, Italy, Sweden and Finland.
Hydrogen is also utilized by fatty acid biohydrogenation in the rumen, which leads to a high proportion of health-threatening saturated fatty acids in foods derived from ruminants and to the formation, followed by the destruction, of health-promoting conjugated linoleic acids (CLA), and to the destruction of n-3, health-promoting fatty acids. The primary aim of this part of our research is to improve the fatty acid composition of ruminant milk and meat for human health. In order to achieve this aim, the microorganisms responsible for fatty acid transformations in the rumen are being identified, the fluxes through pathways of biohydrogenation and desaturation measured, the population sizes of the most significant microbial species evaluated, and ways of altering these fluxes and populations are being investigated. If these objectives can be achieved, it will then be possible, using dietary manipulation or new feed additives, to improve the health profile of fatty acids in ruminant products.
Sub-acute ruminal acidosis (SARA) is a disorder that can afflict all ruminant species, but one that is particularly prevalent in intensively produced dairy and beef cattle. It is thought to result from dysfunction of ruminal microbial ecology. SARA might be regarded as mainly an unseen, and most certainly under-researched, disorder, because its symptoms are those of ill-thrift rather than illness. The pathology is only found clearly upon post mortem inspection. However, next to the ill-thrift, SARA is associated with reduced fibre degradation, reduced feed intake, laminitis and diarrhoea and thereby also increased involuntary culling. Its economic impact is therefore hard to determine exactly. The loss to the UK economy could easily exceed £200M p.a. The welfare justification for investigating SARA is also compelling, as SARA-related illnesses are painful and detrimental to health, particularly laminitis.
The Scottish SARA Consortium, funded by BBSRC, was formed one year ago to investigate:
- If on-farm management practices can be identified that predispose beef and dairy cattle to SARA.
- If remote motion sensing devices mounted around the animal’s neck can give early warning of SARA.
- What is the precise pathology of black patches on the rumen wall?
- If soluble LPS in SARA-susceptible cattle differs from soluble LPS in SARA-resistant cattle.
- The relative importance of the rumen and the hindgut in SARA.
- The precise pathotypes of E. coli present in SARA-susceptible cattle.
- If probiotic bacteria can be isolated from individual SARA-resistant cattle.
Kevin Shingfield, Aberystwyth University (fatty acid metabolism, methane); Veerle Fievez, University of Gent (fatty acid metabolism); Rui Bessa, University of Lisbon (fatty acid metabolism); Margarida Maia, University of Porto (fatty acid metabolism); Mick Watson, University of Edinburgh (metagenomics); Nick Jonsson, University of Glasgow (SARA); Ivan Andonovic, Strathclyde University (SARA); Pekka Huhtanen, Sveriges lantbruksuniversitet, Umeå (methane); Phil Garnsworthy, Nottingham University (methane); Paolo Bani, Catholic University, Piacenza (methane); Sinead Waters, Teagasc, Dublin (methane); Tim McAllister, Lethbridge, Canada; Pierre Taberlet, Grenoble University, France; Chris McSweeney, CSIRO, Brisbane.
2011 TSB Genomics Competition, with Ingenza Ltd. £513,000
2011 EC FP7, FOOD-SEG partner, €23,219 euros (of total 999,915 euros)
2012 Studentship, Commonwealth Scholarship Commission
2012 Framework 7 project RuminOmics, coordinator, €7.7M, 2012-2015
2012 BBSRC Industrial Partnership Award: Sub-acute ruminal acidosis (SARA). Consortium leader. £1.2M, 2012-2015
2012 Technology Strategy Board SPARK, methane £5k
2012 EBLEX (with SRUC) SafeBeef. £280k
2013 BBSRC Studentship with SRUC, methane
Since the Animal Nutrition M.Sc. course ended, no teaching responsibilities
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Member of the FEEDAP panel of the European Food Safety Authority, 2012-2015.
Member of Editorial Boards, Applied and Environmental Microbiology, Animal Feed Science and Technology.
Member of the International Science Foundation assessment committee.
Project adviser, ECO-FCE, Framework 7 project
Project advisor, 'Influence of tannins on fatty acid biohydrogenation' Faculdade de Medicina Veterinária (FMV/UTL), Lisboa;Instituto de Ciências e Tecnologias Agrárias e Agro-Alimentares - Porto (ICETA-Porto/UP)
Project reviewer, Australian National Livestock Methane Program, Livestock Production Innovation, Meat & Livestock Australia.