Acknowledgements

We are grateful to Dr. Leyden Baker, International Livestock Research Institute, who directed the research, for permission to use data collected during the experiment for this case study. Teachers and other users of this case study are welcome to use the data for further analysis but not to publish any results without permission from the International Livestock Research Institute. We also thank Dr. John Rowlands for guidance in developing this case study.

Unless otherwise indicated the photographs were taken by Dave Elsworth