My thanks are due to FAO for the provision of funds to enable me to undertake this study. It would not have been attempted without the persuasion of Ed and Frances Rossmiller on whose methodological approach it is based. I am grateful to them for the stimulation of discussion about their paper and a helpful correspondence. Equally, after retirement from a career in the dairy industry, I would not have re-visited the subject without the encouragement to do so from my wife, Margaret.
I would like to acknowledge help from the following people who either read parts of the draft and/or provided me with material: Mr John Empson (United Kingdom); Mr Paul Allsop and Mr Peter Willis of Milk Marque; Mr Ian Wakeling, National Dairy Council; Drs Harm Schelhaas (the Netherlands); Dr Antonella Pederiva (Italy); Mr Philippe Jachnik (France); Mr Preben Mikkelsen and colleagues of the Danish Dairy Board; Dr Julie Smith and Mr Sion Roberts of the National Farmers' Union of England and Wales. My warm thanks to them all; none of course are responsible in any way for errors or omissions in the work.
Finally, it would have been impossible for me to produce this study without the assistance of Mrs Angela Angel who coped patiently with my handwriting and then with numerous changes of mind that follow discussion and afterthought.
