Understanding, quantifying, and tracking atmospheric methane and emissions is essential for addressing concerns and informing decisions that affect the climate, economy, and human health and safety. Atmospheric methane is a potent greenhouse gas (GHG) that contributes to global warming. While carbon dioxide is by far the dominant cause of the rise in global average temperatures, methane also plays a significant role because it absorbs more energy per unit mass than carbon dioxide does, giving it a disproportionately large effect on global radiative forcing. In addition to contributing to climate change, methane also affects human health as a precursor to ozone pollution in the lower atmosphere. Improving Characterization of Anthropogenic Methane Emissions in the United States summarizes the current state of understanding of methane emissions sources and the measurement approaches and evaluates opportunities for methodological and inventory development improvements. This report will inform future research agendas of various U.S. agencies, including NOAA, the EPA, the DOE, NASA, the U.S. Department of Agriculture (USDA), and the National Science Foundation (NSF).

As world population increases, demand for food and particularly animal products is expected to grow substantially. Because of limited area for expansion of animal agriculture and growing consumer concern for the environmental impact of animal production, gains in animal efficiency will have to be part of the solution. This book addresses key issues of how energy and protein are utilized and interact in farm animals from the molecular to the whole animal and even to the herd or group level of organization. It contains state-of-the-art research and reviews on several topics of nutrient utilization and metabolism from top scientists worldwide. Key issues addressed include energy/protein interactions, methodology such as in vitro and in vivo techniques, regulation including pre-natal programming and endocrine regulation, modeling and systems biology (including a tribute to the late Professor R. Lee Baldwin of the University of California, Davis, a leader in the field), products and health of animals, tissue metabolism, and environmental sustainability in agriculture. This book is a valuable resource for researchers, students, policy makers, producers and industry professionals believing that a better understanding of metabolism and nutrition of farm animals is part of the solution.

The use of indirect calorimetry to measure the heat production of men and animals has increased rapidly since the pioneering work of Lavoisier. Measurement of the consumption of oxygen and production of carbon dioxide are the basis for the measurement of heat production. Today, applications of indirect calorimetry are available in many species. Combining these measurements with accurate climate control, recording of physical activity and feed intake, use of stable isotopes and sophisticated modelling techniques allow scientists to make progress in various research areas. This book provides a scientific basis for indirect calorimetry, dealing with smart ways to design calorimeters, gas measurements and computational techniques to deal with complex data. Novel techniques allow the connection between short term changes in energy expenditure, protein turnover and substrate oxidation, e.g. using stable isotopes. Various applications of indirect calorimetry are addressed, including heat production measurements in growing animals, hatching eggs, companion animals and in animals housed under heat stress conditions. In addition, various ways of measuring methane emissions are discussed. This book is intended for scientists working or interested in calorimetry or metabolism research, or people designing calorimetry systems, opening their eyes for applications they did not yet think of.

Animals are biological transformers of dietary matter and energy to produce high-quality foods and wools for human consumption and use. Mammals, birds, fish, and shrimp require nutrients to survive, grow, develop, and reproduce. As an interesting, dynamic, and challenging discipline in biological sciences, animal nutrition spans an immense range from chemistry, biochemistry, anatomy and physiology to reproduction, immunology, pathology, and cell biology. Thus, nutrition is a foundational subject in livestock, poultry and fish production, as well as the rearing and health of companion animals. This book entitled Principles of Animal Nutrition consists of 13 chapters. Recent advances in biochemistry, physiology and anatomy provide the foundation to understand how nutrients are utilized by ruminants and non-ruminants. The text begins with an overview of the physiological and biochemical bases of animal nutrition, followed by a detailed description of chemical properties of carbohydrates, lipids, protein, and amino acids. It advances to the coverage of the digestion, absorption, transport, and metabolism of macronutrients, energy, vitamins, and minerals in animals. To integrate the basic knowledge of nutrition with practical animal feeding, the book continues with discussion on nutritional requirements of animals for maintenance and production, as well as the regulation of food intake by animals. Finally, the book closes with feed additives, including those used to enhance animal growth and survival, improve feed efficiency for protein production, and replace feed antibiotics. While the classical and modern concepts of animal nutrition are emphasized throughout the book, every effort has been made to include the most recent progress in this ever-expanding field, so that readers in various biological disciplines can integrate biochemistry and physiology with nutrition, health, and disease in mammals, birds, and other animal species (e.g., fish and shrimp). All chapters clearly provide the essential literature related to the principles of animal nutrition, which should be useful for academic researchers, practitioners, beginners, and government policy makers. This book is an excellent reference for professionals and a comprehensive textbook for senior undergraduate and graduate students in animal science, biochemistry, biomedicine, biology, food science, nutrition, veterinary medicine, and related fields.

Addressing methane emissions from livestock and rice systems is vital for promoting sustainable agriculture and mitigating climate change. This FAO report comprehensively addresses methane emissions in agriculture and their impact on global greenhouse gas levels. By analysing sources, sinks, quantification methods, and mitigation strategies, this publication highlights challenges and opportunities to reduce methane emissions from livestock and rice production systems.

​​This book provides standards and guidelines for quantifying greenhouse gas emissions and removals in smallholder agricultural systems and comparing options for climate change mitigation based on emission reductions and livelihood trade-offs. Globally, agriculture is directly responsible for about 11% of annual greenhouse gas (GHG) emissions and induces an additional 17% through land use change, mostly in developing countries. Farms in the developing countries of sub-Saharan Africa and Asia are predominately managed by smallholders, with 80% of land holdings smaller than ten hectares. However, little to no information exists on greenhouse gas emissions and mitigation potentials in smallholder agriculture. Greenhouse gas measurements in agriculture are expensive, time consuming, and error prone, challenges only exacerbated by the heterogeneity of smallholder systems and landscapes. Concerns over methodological rigor, measurement costs, and the diversity of approaches, coupled with the demand for robust information suggest it is germane for the scientific community to establish standards of measurements for quantifying GHG emissions from smallholder agriculture. Standard guidelines for use by scientists, development organizations will help generate reliable data on emissions baselines and allow rigorous comparisons of mitigation options. The guidelines described in this book, developed by the CGIAR Research Program on Climate Change, Agriculture, and Food Security (CCAFS) and partners, are intended to inform anyone conducting field measurements of agricultural greenhouse gas sources and sinks, especially to develop IPCC Tier 2 emission factors or to compare mitigation options in smallholder systems.