skip to primary navigationskip to content

The limits of livestock intensification

The limits of livestock intensification

Supervisor: Prof Andrew Balmford

Project summary:

Quantifying trade-offs among livestock yields, animal welfare, water and antibiotic use and GHG emissions is essential for progressing towards sustainable intensification. This project will explore these relationships using data on contrasting livestock production systems from the grey and published literature and from industry experts.  Water and GHG footprints will be measured both on- and off-site. Antibiotic use will be measured for current systems, and the likely impacts of future restrictions (potentially necessitating system extensification) will also be explored.  Welfare will be quantified using established proxies (e.g.  drug administration). Correlations among these parameters may identify “win-win-win” systems that combine high yields, high welfare and limited environmental footprints, as well as less promising approaches. 

What the student will be doing:

The successful candidate will collate standardised data on the welfare, economics and environmental impacts of a wide variety of current and potential future production systems, both from the literature and by consulting industry experts (via workshops and direct correspondence). Yields will be measured both in kg protein/ha and profit/ha. Animal welfare will be assessed through the “5 freedoms”, using proxies such as medicine use. Assessment of GHG and water fluxes will involve life cycle analyses where possible. Besides quantifying current antibiotic use, the student will consider antibiotic resistance (in people and animals) and explore possible welfare and environmental impacts of bans or restrictions in use. Characterizing trade-offs among these parameters will help to identify more or less favourable production systems and their sensitivity to the weighting each parameter is given –under business-as-usual trajectories of demand as well as contrasting scenarios (such as lowered demand, greater use of food waste, etc.). 

References:

Eisler, M. C., Lee, M. R., Tarlton, J. F., Martin, G. B., Beddington, J., Dungait, J. A., ... & Misselbrook, T. (2014). Agriculture: Steps to sustainable livestock. Nature, 507(7490), 32.

Tilman, D., & Clark, M. (2014). Global diets link environmental sustainability and human health. Nature, 515(7528), 518-522.

Van Boeckel, T. P., Brower, C., Gilbert, M., Grenfell, B. T., Levin, S. A., Robinson, T. P., ... & Laxminarayan, R. (2015). Global trends in antimicrobial use in food animals. Proceedings of the National Academy of Sciences, 112(18), 5649-5654.