Animal production systems have changed dramatically over the last two decades. Knowledge of energy metabolism and environmental physio logy has increased as appears from many textbooks on these disciplines. The contents of the symposia on energy metabolism of farm animals show this and they have initially focussed on feed evaluation and later on com parative aspects of energy metabolism. They show part of the progress being made. Application of knowledge of energy metabolism for animals has a long history since Lavoisier. In addition to this, studies about the environ mental requirements of animals have shown that we are still far from ac curate assessment of these requirements in terms of nutrients and ener gy. I n model studies on energy metabolism researchers have recognized the interaction between the environment and the energy requirements of animals. Estimation of energy requirements has been done in physiolo gical, physical and behavioural studies. The impact of conditions as en countered by animals in various production systems has been approached from different viewpoints related to these different disciplines. In addi tion, various kinds of infections (bacterial, parasitic: subclinical, clini cal) have been evaluated only recently with regard to their effect on pro tein and/or energy metabolism and thus on production. People working in the field of feed evaluation have defined how che mical and physical properties of nutrition infiuence energy to be derived for maintenance and production.

Studies in the Agricultural and Food Sciences: Energy Metabolism is a compilation of works on the energy metabolism in animals, especially animals of agricultural importance. The book is written by authoritative workers in the field and is divided into six parts; each chapter is based on a selected paper presented at the Eighth Symposium on Energy Metabolism held at Cambridge in September 1979. The text discusses feed evaluation; use of energy for maintenance and growth; and simulation models for energy exchange and growth. The book also covers the comparative aspects of energy metabolism; use of energy in production and lactation; and metabolic responses in the growing animal. The monograph is recommended for those who plan to study about energy metabolism of farm animals and its relationship with certain biological processes. The book will also appeal to those who develop feeds and methods that can help improve energy metabolism of farm animals.

The Proceedings of the 14th Symposium on Energy Metabolism of Farm Animals, held in Northern Ireland in September 1997, comprises 85 original contributions by leading scientists from over 20 countries around the world. In keeping with previous Symposia in the series, held under the auspices of the European Association for Animal Production, this book contains papers which provide the latest research on the energy metabolism and other aspects of the physiology of a wide variety of farmed animals. Highlights include a comprehensive review of the current state of research on leptins and their potential applications in animal production, and a large section relating to organ and tissue metabolism, with major contributions from the USA, UK, France, Germany and Denmark. An important strength of the book is the diversity of species covered. For example, the sections on modelling and feed evaluation relate to pigs, sows, broiler chickens, laying hens, turkeys, lambs, beef and dairy cattle and fish. There are also substantial contributions on lactation and reproduction, growth, environmental aspects and maintenance. This book is essential reading for research workers in animal science, particularly those concerned with nutrition and feed evaluation.