Consistent ozone-induced decreases in pasture forage quality across several grassland types and consequences for UK lamb production

Felicity Hayes*, Gina Mills, Laurence Jones, John Abbott, Mike Ashmore, Jeremy Barnes, J. Neil Cape, Mhairi Coyle, Simon Peacock, Naomi Rintoul, Sylvia Toet, Kerstin Wedlich, Kirsten Wyness

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


In this study we have demonstrated that rising background ozone has the potential to reduce grassland forage quality and explored the implications for livestock production. We analysed pasture samples from seven ozone exposure experiments comprising mesotrophic, calcareous, haymeadow and sanddune unimproved grasslands conducted in open-top chambers, solardomes and a field release system. Across all grassland types, there were significant increases in acid detergent fibre, crude fibre and lignin content with increasing ozone concentration, resulting in decreased pasture quality in terms of the metabolisable energy content of the vegetation. We derived a dose-response function for metabolisable energy of the grassland with ozone concentration, applicable to a range of grassland types, and used this to predict effects on pasture quality of UK vegetation at 1km resolution using modelled ozone data for 2007 and for predicted higher average ozone concentrations in 2020. This showed a potential total reduction in lamb production in the UK of approximately 4% in 2020 compared to 2007. The largest impacts were in geographical areas of modest ozone increases between the two years, but where large numbers of lambs were present. For an individual farmer working to a very small cost margin this could represent a large reduction in profit, both in regions where the impacts per lamb and those where the impacts per km2 of grazing land are largest. In the short term farmers could adapt their lamb management in response to changed forage quality by additional supplementary feed of high metabolisable energy content. Nationally this increase in annual additional feed in 2020 compared to 2007 would be 2,166 tonnes (an increase of 0.7%). Of added concern are the longer-term consequences of continual deterioration of pasture quality and the implications for changes in farming practices to compensate for potential reductions in livestock production capacity.

Original languageEnglish
Pages (from-to)336-346
Number of pages11
JournalScience of the Total Environment
Issue numberPt A
Early online date18 Nov 2015
Publication statusPublished - 1 Feb 2016

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© 2015 Elsevier B.V. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details


  • Air pollution
  • Grazing
  • Lambs
  • Livestock production
  • Metabolisable energy
  • Ozone
  • Pasture quality
  • Sheep
  • Grassland
  • Environmental Monitoring
  • United Kingdom
  • Meat
  • Animal Husbandry/methods
  • Animals
  • Air Pollutants/analysis
  • Ecosystem
  • Ozone/analysis
  • Livestock
  • Animal Feed

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