This volume examines dynamic interactions between the calculative and speculative practices of commerce and the fruitfulness, variability, materiality, liveliness and risks of nature. It does so in diverse environments caught up in new trading relationships forged on and through frontiers for agriculture, forestry, mining and fishing. Historical resource frontiers are understood in terms of commercial knowledge systems organized as projects to transform landscapes and environments. The book asks: how were environments traded, and with what environmental and landscape consequences? How have environments been engineered, standardized and transformed within past trading systems? What have been the successes and failures of economic knowledge in dealing with resource production in complex environments? It considers cases from northern Europe, North and South America, Central Africa and New Zealand in the period between 1750 and 1990, and the contributors reflect on the effects of transnational commodity chains, competing economic knowledge systems, environmental ignorance and learning, and resource exploitation. In each case they identify tensions, blind spots, and environmental learning that plagued commercial projects on frontiers.

Given the importance of livestock to the global economy, there is a substantial need for world-class reference material on the sustainable management of livestock in diverse eco-regions. With uncertain climates involving unpredictable extreme events (e.g., heat, drought, infectious disease), environmental stresses are becoming the most crucial factors affecting livestock productivity. By systematically and comprehensively addressing all aspects of environmental stresses and livestock productivity, this volume is a useful tool for understanding the various intricacies of stress physiology. With information and case studies collected and analyzed by professionals working in diversified ecological zones, this book explores the influence of the environment on livestock production across global biomes. The challenges the livestock industry faces in maintaining the delicate balance between animal welfare and production are also highlighted.

This comprehensive research book represents the first complete integration of current knowledge in this area. It addresses issues associated with poultry breeding particularly by examining quantitative and molecular genetics and the uses of transgenic technology. A special section covers the important area of disease resistance and transmission.

Factors Affecting Calf Crop summarizes the latest information available from leading cattle physiologists and geneticists regarding factors known to influence the production of live calves at weaning. You get practical information on management techniques for improving reproduction efficiency in the herd. You'll also learn about the functioning of the reproductive system and how this may affect reproductive processes in the cow herd. Managers will benefit from a clearer understanding of the factors known to limit efficient reproduction, while veterinarians and other professionals who advise cattlemen will appreciate the substantial reference material and color photographs for defining cow condition scores. Color photographs are also used to illustrate the discussions of testicular thermographies and their applications. Other chapters in the book cover developments in improving reproductive performance of the replacement heifer, the brood cow, and the bull. Topics on reproduction include physiology/endocrinology, the use of growth promotants, genetics and physiological and economic considerations in selecting the age to breed heifers, heritability of fertility, length of the breeding season, prepartum and postpartum nutrition, nursing by the calf, cloning of embryos, and much more.