Prolific sheep. 1996

Prolific sheep. 1996

19 obstacle is the hyperacute rejection of the transplant by the recipient immune system. The complement system initiates a cascade of first line def...

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obstacle is the hyperacute rejection of the transplant by the recipient immune system. The complement system initiates a cascade of first line defence events leading to the destruction of the foreign material within minutes. The presence of complement masking or shield proteins prevents attacks against the recipients own cells. Transgenic animals are being developed which express human shield proteins on the surface of their organs which, in theory should escape destruction in recipient humans. Two of the leading companies developing transgenie animals as organ donors are Imutran of Cambridge in the UK and DNX of Princeton, New Jersey, USA. Pigs are the favoured species as the size, anatomy and physiology of pig organs are compatible with humans. Also there are few pig diseases that can be transmitted to humans. Both companies have transgenic pigs organs which are experimentally transferred to monkeys. The research raises scientific and ethical issues. Some ethical issues concern animal welfare. Also people have expressed reluctance in some surveys against accepting animal organs. From: Eric A. Wong, Department of Animal and Poultry Sciences, Virginia Tech. [email protected] Note: In January 1997, the UK government placed a temporary ban on xenotransplants in the UK until the risks of transmitting animal diseases to humans has been further examined. BOOK REVIEWS Goat Production Systems in the Mediterranean. 1995. Eds.: A. El. Aich, S. Landau, A. Bourbouze, R. Rubino and P. Morand-Fehr. EAAP Publication No. 71. EAAP/FAO/ CIHEAM Cooperative Network on Sheep and Goat Research. Published by Wageningen Pers, PO Box 42, 6700 A Wageningen, The Netherlands. ISBN 90-7413425-4 HB. 239 pp. This book can be read at various levels. First it is an exhaustive description of the present position of goat production systems in the Mediterranean: southem Spain, French Mediterranean, southern Italy, Greece, Turkey, Israel, Egypt, Tunisia, AlgeriaKabylia and Morocco. It is especially valuable that almost all ten papers give information in the same

sequence: the historic evolution of goat production, available statistics, experimental results and performance recording, economy, production systems, and present and future developments. Of course, the efficiency of the co-ordination is not perfect and some papers are less informative than others. Also, we can stress the lack of information on some parts of the Mediterranean. However, this remarkable effort finally provides a comparative study of goat production systems which is a highly effective result of a co-ordinated study and is a significance contribution to the many components of the Mediterranean mosaic. This book also demonstrates the usefulness of the principles and concepts of the analysis of production systems applied to goat production especially with the two papers carried out by Santucci et al. on the Corsica situation in France, and by Bourbouze who outlines the common thread of the various contributions. Even a quick read of this book makes one aware of the value of the introductory paper by Bourbouze and the final comparative study, which are really the keys to understanding this ambitious work. Then, the ten national reports can be considered as a reference source of rich information brought together in this unique and useful document. Finally, the book may be likened to a “judicial defence’ ’ of goat production in the Mediterranean mobilising three positive arguments: its capacity for adaptation to constraints and hazards, its human and economic flexibility, and also its remarkable productive potentials. Dr. Jean-Claude Flamant INRA Castanet-Tolosan, France. Prolific Sheep. 1996. M.H. Fahmy (Ed.). Commonwealth Agricultural Bureau, Waiiingford, Oxon., 0x10 8DE, UK. 542 pp. HB ISBN 0 85198 983 7. After the World War II, the increasing importance of meat in sheep production created interest in improving prolificacy for better returns per unit of production. Some attempts to increase the litter size by selection failed, because of the low heritability of multiple births. Thus, attention was directed to the great breed differences in litter size. Until the beginning of the 1960s little was known about the exis-


tence of prolific breeds, because of their remote locations and lack of studies. Then, research institutes in the UK and France started to acquire representatives of prolific breeds like Finnsheep and Romanov for experimentation. The studies showed that breeds differ not only in litter size but also in many other components of reproduction. Several other prolific breeds were found, generating a wide interest in studying their usefulness. Intensive research and efforts to utilise prolificacy has provided information on a large number of economic and physiology traits in many environments. In the 198Os, the discovery of the Booroola gene in Australia added a new dimension for increasing prolificacy. It was imported to America and Europe, where intensive research to locate the gene and use it commercially has been under way. Later, similar single genes were discovered in breeds that showed unexpectedly high prolificacy. The availability of improved techniques for transportation, artificial insemination and embryo transfer facilitated the move of prolific breeds across continents, making it possible to develop new prolific breeds more suitable to local conditions. Many researchers found it more practical to improve sheep production by introducing prolificacy from imported breeds to local base populations, than by selecting for this in the latter. Most of the knowledge used in various aspects of sheep production was acquired from non-prolific breeds, and could not be applied to prolific sheep. Studies made on these, or comparisons with non-prolific sheep thus became important for understanding the physiology, nutritional requirements, diseases, management and appropriate breeding methods. Results of such studies have accumulated in various scientific journals all over the world. It appeared important to gather this extensive information on prolific sheep in one volume and to summarise the research results obtained, to provide an easy and accessible reference tool for people interested in the subject. The book comprises 35 articles (chapters or subchapters) written by 52 experienced researchers from 18 countries, from all continents. In the preface, the editor describes the development of interest in prolific breeds, the finding of single genes for prolificacy, and the modem techniques, which have facili-

tated transfer of breeds and genes between countries, and utilisation of these. The late grand lady of Australian sheep breeding, Dr. Helen Turner discusses the advantages and disadvantages of big litters and of selection for them. After a short chapter on the historical background and recognition of prolific sheep, there is a long chapter (195 pp.) on prolific sheep breeds, divided into 13 subchapters. Eight of these concern breeds in which prolificacy is assumed to be a polygenic trait. A total of 21 such breeds is described on the basis of published studies. The largest space is devoted to the Finnsheep and Romanov, the first prolific breeds introduced to experiments on prolificacy. The descriptions include origin and development, physical appearance, wool cover, biochemical polymorphisms, reproductive and productive performances of both sexes, sexual behaviour and adaptability to different conditions, partly as compared to other breeds in the same experiments. Three subchapters describe four breeds in which prolificacy seems to be controlled by a single major gene or group of closely linked genes affecting on ovulation rate. One subchapter shortly describes nine less known and rare prolific breeds and another one 17 newly developed prolific breeds. There are chapters on the economic importance of prolificacy and on the spread of prolific sheep to various countries. A long one (170 pp.) discusses the use of prolific sheep in various global regions for crossbreeding and breed formation. There are separate chapters for the feeding and management (intensive and extensive), reproductive physiology and endocrinology, the reproductive behaviour of prolific sheep, diseases associated with prolificacy, detection of major genes for prolificacy and strategies for their use, and finally on the future research opportunities and prospects. The book is very thorough and of high quality. The breed descriptions are made according to a model given by the editor, giving coherence to them. The authors have themselves worked on the aspects of development, comparison and utilisation of prolific sheep treated by them. The book is useful especially to researchers involved with prolific sheep in various sectors of science, and to graduate and postgraduate students of animal production. Also producers and other people interested in sheep with


high productivity or in knowing more about prolific sheep and their utilisation can benefit of it. It is well written and has a total of 1,420 literature references, of which 99% stem from the time since 1960. There are 29 photos, 19 figures and 147 tables, some of them rather long, and an alphabetical subject index of 8 pages. Kalle Maijala Professor Emeritus Agricultural Research Centre, Finland. Protein Metabolism and Nutrition. 1996. Eds.: A.F. Nunes, A.V. Portugal, J.P. Costa and J. Bibero. Proc. of 7th International Symposium, Vale de Santar6m, Portugal in 5 / 95. EAAP Publication No. 81. Published by [email protected] Zootknica National, Institute National de [email protected] Agkia, Fonte Boa - Vale de Sant&m, 2000 Santar6m, Portugal. ISBN 972-8126-01-8. HB. 528 PP. As may be expected, these Proceedings assemble first a series of authoritative state-of-the-art reviews on several aspects of protein metabolism and nutrition. They also present a multitude of short communications and posters illustrating current European research efforts on the subject. The editors have separated the communications into three topics, dealing with protein utilization, protein metabolism and metabolic control and, last but not least, production efficiency and the impact on the product quality and environment. Each topic contains two main sessions, a limited number of short papers and a large number of posters. All short papers, posters and the main sessions on topic one, were separated into ruminant and non-ruminant species. Finally, the reports of plenary sessions that followed four round tables are presented, covering methods for the study of protein supply, requirement and metabolism; protein evaluation systems and modes; protein metabolism, animal product quality and human health; and finally, antinutritive factors in protein metabolism. Vernon Young opens the Proceedings with a very detailed keynote lecture on progress in the knowledge of protein and amino acid metabolism and nutrition since the last symposium. It is an example of a perfect textbook chapter both for students and scientists. More condensed information on protein

metabolism in relation to oxidative stress and fish nutrition follows. Young’s introduction highlights the complexity and importance of mechanisms regulating protein turnover in animal tissue. It may be noted in passing that this introduction as well as the title of the symposium includes man, although none of the other papers deals with that species!? Indeed, it seems that the preponderance of the following papers deal with digestion aspects in ruminants. In the first session, the latter species receives attention in relation to protein utilisation where Hvelplund and Madsen emphasize the need to understand better the process of urea recycling to the rumen. This is done, more in relation to environmental needs than to production needs. For non-ruminant species, a survey of the 28 short papers and posters suggest the need for more research efforts establishing amino acid requirements for aquatic and fur animals for practical feed formulation. Also standardization of methods for measuring protein digestion appears an urgent need. An impressive series of 40 short papers and poster communications related to ruminants highlight mainly classical rumen digestion problems, including, for example, the composition of rumen bacteria and the use of milk urea to evaluate protein nutrition status. Protein metabolism and its control are covered well through clearly presented knowledge, from Seerp Tamminga and John MacRae with associates. The latter underline many methodological traps to be avoided in measuring turnover. A smaller total of 40 short papers and posters is presented, separated into whole animal and specific organ aspects. Although many papers deal with subjects that have been recurrent themes of the past 15 years and progress in some areas appears to be very slow, some interesting topics are treated: peptide metabolism, gut microbial amino acid synthesis, amino acid-tissue interactions and regulation. Basic research is also directed towards tilling in gaps in the knowledge of nutrient flow in organs, so that a better balance can be provided between nutrient availabilities and animal requirements. The third session presents perhaps the most important subjects: protein metabolism as related to product quality and the environment. Again, the authority of someone like Peter Buttery guarantees the quality of the main conference on product quality. The recent knowledge on the relation cal-