animals that produce the meat — is increasingly treated as an integral feature of product quality along with taste, texture and safety, rather than as a separate issue of concern only to a minority. In this respect, the idea that ‘‘good welfare is good for meat quality’’ is becoming a truism. That theme is not developed in this book, but makes the book even more relevant than it would have been a few years ago.
The book starts with general chapters, including one on ‘‘Solving livestock handling problems in slaughter plants’’ by Temple Grandin, which fits well with Gregory’s coverage of other processes. Then there are three chapters that give detailed accounts of pre- and post-slaughter physiology, particularly in muscle. Chapters on cattle, sheep, pigs, poultry and fish follow, and then there is a return to the general approach, with chapters on processed meats, stunning and slaughter.
This is not an easy read for those unfamiliar with physiology or the meat industry. Indeed, it might better have been called ‘‘Meat Science and Animal Welfare’’. For example, the variable pHult is used from page 5 onward, but is not explained until page
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112. It is the pH of meat 24 h after slaughter. There is a short List of Synonyms such
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as ‘‘weasand’’ for oesophagus , which could usefully have been expanded into a glossary of both scientific and trade jargon. Some sections have summaries or conclu-sions at the end but this is not done consistently, and it is often difficult to identify the most important details of physiology or of appropriate animal treatment in the mass of material. As a last criticism, many statements are not referenced. There is an intriguing mention on page 25 of nausea in ‘‘a decorticate man subjected to a rough airplane journey’’, and it is frustrating not to be able to follow this up.
The book is well produced with few errors. There is more emphasis on description than on prescription, but Gregory’s work has also reached livestock managers by other routes. Certainly, people who criticize animal management practices should read this book because it contains details that are relevant to assessing these practices: for example that ‘‘The physical signs shown by birds that do not develop a cardiac arrest at
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stunning are sometimes wrongly diagnosed as signs of consciousness’’ page 238 . However, there are also many descriptions of things that can and do go wrong in animal handling and slaughter, and suggestions for how these can be avoided for improvement of both animal welfare and meat quality.
This is an important book that presents a comprehensive review, description and explanation of the links between animal welfare and meat quality. Many of these effects are mediated by behaviour, so the book is a valuable resource for applied ethologists concerned with animals during transport, lairage and slaughter.
Animal groups in three dimensions
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Julia K. Parrish and William M. Hamner Editors . Cambridge University Press, 1997
Ždistributed 1998 , 384 pp., UK£60.00, US$90.00, ISBN 0-521-46024-7 hardback. Ž .
‘‘A sheep on its own is not a sheep’’, as Ron Kilgour used to say. The idea must apply even more to a starling, which may be a member of a flock wheeling in flight with synchrony accurate to a few microseconds. Or to a mullet, which joins a school hundreds of meters long, so dense that oxygen concentration is halved at the trailing end and fish ‘‘roil’’ the surface either to obtain oxygen directly from the air or to increase gas exchange in the surface water.
This is a fascinating book. We learn that in a turning flock of birds such as starlings, an individual bird on the left ends on the right, because they all turn with similar arc, not in parallel. If you have an airplane, do not try this at home. People have attributed synchrony to mechanisms such as thought transference or electromagnetic fields from a leader affecting the brains or neuromuscular systems of followers. A more likely mechanism is threshold influence of neighbours. If one of your neighbours deviates, you ignore her and she will probably correct the deviation. If many neighbours deviate, you copy them — as rapidly as possible to avoid a crash and to use the information that they
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have presumably obtained such as sighting of a predator .
The book was derived from a workshop with delegates mostly from North America, with some from Japan and Australia. After an introductory chapter, the book is divided into four sections: Imaging and measurement; Analysis; Behavioural ecology and evolution; and Models. It is an attractive book with a good number of illustrations, including photographs. The style of the chapters varies, with some very readable and others more mathematical.
Much of the understanding of groups conveyed here is relevant to species of more direct interest to readers of this journal. Food-restricted broiler breeders fill much of the time between their short meals with waves of movement that are similar in two dimensions to those of starlings in three. The preference of cows for lying within groups rather than at the edge is likely to be the same anti-predation strategy as is discussed here in many species including arthropods. Furthermore, the studies of behaviour described have many potential applications — from fishing, through control of bird flocks over airfields, to conservation of trees attacked by swarming pests.
The book also has other messages for applied ethologists who, in commonality with the authors, are concerned to address complex problems. First, a multidisciplinary approach is very productive. Second, delineation of a topic or problem may be useful to focus ideas but should not exclude contributions from outside the boundary. Thus, while
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birds were using uplift from the wing-tip vortices of those in front of them. This is a testable hypothesis and there has been some evidence found in support. Fourth, however, all good answers raise more questions. If it is an advantage to follow others, why does any bird stay in front of the V?
Michael C. Appleby Institute of Ecology and Resource Management, UniÕersity of Edinburgh, West Mains Road, Edinburgh EH9 3JG, UK
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