Download or read book Identifying Potential Sources of Variation in Residual Feed Intake in Beef Cattle written by Kevin S. Shaffer and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sources of Biological Variation in Residual Feed Intake in Beef Cattle written by Phillip Allan Lancaster and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Objectives of this study were to characterize residual feed intake (RFI) in growing calves and to examine relationships with growth, carcass composition, physiological indicators, energy metabolism and reproduction. To accomplish these objectives, multiple experiments were conducted. In all experiments, RFI was calculated as the difference between actual DMI and expected DMI from linear regression of DMI on mid-test metabolic BW and ADG. To examine the relationships between RFI and rate and composition of growth, and reproduction an experiment was conducted with postweaning Brangus heifers (N = 348). Measures of carcass composition (longissimus muscle area, LMA; and 12th rib fat thickness, BF) were obtained by ultrasound at the start and end of each experiment. To determine if serum IGF-I concentration is associated with RFI, two experiments were conducted with Angus bulls and heifers (N = 95) divergently selected for serum IGF-I concentration. To evaluate relationships with energy metabolism, calves with low and high RFI were selected for determination of heart rate as an indicator trait for energy expenditure (4 experiments) and liver mitochondrial function (3 experiments). Residual feed intake was not correlated with ADG, but was positively correlated with gain in BF such that the more efficient calves were leaner. Calves from the low IGF-I selection line had lower RFI suggesting that RFI and IGF-I are related and that IGF-I could be used as an indicator trait to aid in selection for improved RFI in Angus cattle. Calves with low RFI had lower energy expenditure and greater mitochondrial acceptor control ratios than calves with high RFI suggesting improved regulation of energy metabolism. A similar percentage of heifers with low RFI attained puberty as those with high RFI by the end of the experiment. Results from this study indicate that producers can utilize RFI to select for improved feed efficiency with minimal impact on growth, carcass composition and reproduction.
Download or read book Biological Basis for Variation in Residual Feed Intake in Beef Cattle written by Emma Richardson and published by . This book was released on 2002 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Feed Efficiency in the Beef Industry written by Rodney A. Hill and published by John Wiley & Sons. This book was released on 2012-09-11 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Feed Efficiency in the Beef Industry provides a thorough and concise overview of feed efficiency in beef cattle. It frames the great importance of feed efficiency to the industry and details the latest findings of the many scientific disciplines that intersect and aim to improve efficient and sustainable production of nutritious beef. The vast majority of production costs are directly tied to feed. With increased demand for grains to feed a rapidly increasing world population and to supply a new demand for alternative fuels, feed costs continue to increase. In recent years, the negative environmental impacts of inefficient feeding have also been realized; as such feed efficiency is an important factor in both economic viability and environmental sustainability of cattle production. Feed Efficiency in the Beef Industry covers a broad range of topics ranging from economic evaluation of feed efficiency to the physiological and genetic bases of efficient conversion of feed to high quality beef. Chapters also look at how a fuller understanding of feed efficiency is leading to new selective breeding efforts to develop more efficient cattle. With wide-ranging coverage from leading international researchers, Feed Efficiency will be a valuable resource for producers who wish to understand the complexities, challenges, and opportunities to reduce their cost of production, for students studying the topic and for researchers and professionals working in the beef industry.
Download or read book Feed efficiency in swine written by John F. Patience and published by Springer Science & Business Media. This book was released on 2012-10-15 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'Feed efficiency in swine' has been prepared as a comprehensive treatise on the current state of our understanding of this topic which is so important to the pork industry. Each chapter is written by international authorities who understand both the science and application of their topic area. The book provides detailed insight into the many factors affecting feed efficiency, ranging from diet processing to herd health, from nutrition to physiology and from day-to-day barn management to the adoption of advanced technologies. The authors explain such practical aspects as the challenge of interpreting feed efficiency information obtained on farm or the role of liquid feeding. The authors also delve into more scientific topics such as amino acid or energy metabolism or animal physiology. This book is written for people who have a technical interest in pork production, including nutritionists, geneticists, farm management specialists, veterinarians, other academics and, of course, pork producers.
Download or read book Determining Biological Sources of Variation in Residual Feed Intake in Brahman Heifers During Confinement Feeding and on Pasture written by Robert O. Dittmar and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Objectives were to characterize residual feed intake (RFI) and determine the phenotypic correlation between performance, feed efficiency, and other biological measurements in Brahman heifers, as well as the relationship between RFI determined in confinement and measurements of grazing activity on pasture. Three separate 70 d feeding trials were performed, and RFI was determined as the residual between actual and predicted dry matter intake (DMI) for a given level of production. Brahman heifers (n = 103; 5-to-9 mo of age) were individually limit-fed a pelleted 12% CP complete ration daily in Calan gates. Weekly body weight (BW) and DMI data were collected, and predicted DMI was determined by linear regression of actual DMI on mid-test metabolic BW. Ytterbium chloride was used to evaluate digestive kinetics, and fecal samples were collected to determine fecal volatile fatty acids (VFA) concentration and determine apparent dry matter digestibility (DMD) utilizing acid insoluble ash as an internal marker. Measurements of temperament were evaluated on all heifers at weaning. High (n = 6) and low (n = 6) RFI heifers (Exp. I) grazed fescue and ryegrass to determine variation in grazing behavior, DMI, and apparent DMD. Data from all three experiments were pooled, and RFI was not correlated with average daily gain (ADG), DMI, BW, partial efficiency of gain, feed conversion ration, fecal VFA concentration, or any measures of temperament. There were no significant differences in digestive kinetics between the RFI efficiency groups. Fecal samples taken for acid detergent insoluble ash (ADIA) determination were not collected at frequent enough intervals to account for weekly variation in fecal ADIA concentration. Pasture measurements were not different between the efficiency groups for heifers evaluated for grazing behavior, as well as estimated intake as a proportion of BW, or apparent DMD. Results of this study suggest that Bos indicus cattle appear to have similar efficiency traits as Bos taurus and Bos indicus influenced cattle, making this measure of efficiency equally as valid for use in both types of cattle. This indicates that selection based on RFI can be made to increase feed efficiency without affecting ADG or BW in Brahman cattle.
Download or read book Biology of Domestic Animals written by Colin G. Scanes and published by CRC Press. This book was released on 2017-09-01 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is increasing interest in the biology of domestic animals ranging from genomics, transcriptomics, metabolomics, nutritional physiology, and systems biology. This book touches on all of these, with a particular focus on topics such as domestic animals as comparative models to humans, molecular regulation of growth, metabolic efficiency, reproduction, and the impact of stress on growth and development. The book concludes with a discussion on the current and future directions for researchers.
Download or read book Factors Contributing to Variation in Residual Feed Intake in Mature and Growing Beef Animals written by Claire Fitzsimons and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tackling Climate Change Through Livestock written by Food and Agriculture Organization of the United Nations and published by Food & Agriculture Org.. This book was released on 2013 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Greenhouse gas emissions by the livestock sector could be cut by as much as 30 percent through the wider use of existing best practices and technologies. FAO conducted a detailed analysis of GHG emissions at multiple stages of various livestock supply chains, including the production and transport of animal feed, on-farm energy use, emissions from animal digestion and manure decay, as well as the post-slaughter transport, refrigeration and packaging of animal products. This report represents the most comprehensive estimate made to-date of livestocks contribution to global warming as well as the sectors potential to help tackle the problem. This publication is aimed at professionals in food and agriculture as well as policy makers.
Download or read book Neural Networks with R written by Giuseppe Ciaburro and published by Packt Publishing Ltd. This book was released on 2017-09-27 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncover the power of artificial neural networks by implementing them through R code. About This Book Develop a strong background in neural networks with R, to implement them in your applications Build smart systems using the power of deep learning Real-world case studies to illustrate the power of neural network models Who This Book Is For This book is intended for anyone who has a statistical background with knowledge in R and wants to work with neural networks to get better results from complex data. If you are interested in artificial intelligence and deep learning and you want to level up, then this book is what you need! What You Will Learn Set up R packages for neural networks and deep learning Understand the core concepts of artificial neural networks Understand neurons, perceptrons, bias, weights, and activation functions Implement supervised and unsupervised machine learning in R for neural networks Predict and classify data automatically using neural networks Evaluate and fine-tune the models you build. In Detail Neural networks are one of the most fascinating machine learning models for solving complex computational problems efficiently. Neural networks are used to solve wide range of problems in different areas of AI and machine learning. This book explains the niche aspects of neural networking and provides you with foundation to get started with advanced topics. The book begins with neural network design using the neural net package, then you'll build a solid foundation knowledge of how a neural network learns from data, and the principles behind it. This book covers various types of neural network including recurrent neural networks and convoluted neural networks. You will not only learn how to train neural networks, but will also explore generalization of these networks. Later we will delve into combining different neural network models and work with the real-world use cases. By the end of this book, you will learn to implement neural network models in your applications with the help of practical examples in the book. Style and approach A step-by-step guide filled with real-world practical examples.
Download or read book Feed Evaluation written by P. O. Osuji and published by ILRI (aka ILCA and ILRAD). This book was released on 1993-01-01 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Livestock s Long Shadow written by Henning Steinfeld and published by Food & Agriculture Org.. This book was released on 2006 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The assessment builds on the work of the Livestock, Environment and Development (LEAD) Initiative"--Pref.
Download or read book Identification of Feed Intake Traits Related to Beef Reproductive Improvement written by Cameron Alexander Olson and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reproductive efficiency in the Western Canadian beef cow herd has not improved over the past 3 decades, despite consistent and measurable improvement in several related areas of production. The general objective of this thesis was to evaluate the relationships between early-observation traits (feeding behaviour), weight change, and reproductive efficiency in beef cows. Estimates of total dry matter intake and the relationship between residual feed intake (adjusted for body composition; RFIFAT) observed in heifers and mature cows were also evaluated as traits of interest and use to the Canadian beef industry. Chapters 3 and 4 investigated the relationship between feeding behaviours and reproductive efficiency and provided phenotypic and genetic correlations that may be of use in selecting heifers with greater reproductive potential if those heifers have feeding behaviours reported. Feeding behaviour and reproductive efficiency were both correlated with dry matter intake; feeding behaviours that promote dry matter intake may be useful in the identification of heifers with greater reproductive potential. Chapter 5 evaluates the usefulness of tracking cow weights over time and the usefulness of comparing cow weights to an idealized growth curve estimation. Generally, cows that gained weight over time were more likely to be culled for reproductive failure, and the same was true for cows that were heavier than their estimated body weight. Producers may be able to use weight-monitoring technology currently available and in development to identify cows that abort their calves after a positive pregnancy evaluation and remove them from their herd at a time when feed resources are expensive. Chapter 6 was a comprehensive and unique estimation of cow dry matter intake over time, including energy estimates based on birth, weaning, residual feed intake tests as a heifer and as a cow, and subsequent calving events with associated energy expenditures for milk production. These estimates were compared to genomic retained heterozygosity, breed composition, and winter-feeding environment to evaluate the effects of those variables on dry matter intake predictions. Chapter 7 investigated the relationship between heifer residual feed intake and residual feed intake observed in the same animals as mature cows. Residual feed intake in heifers can be used to select cows that maintain a proportion of their efficiency observed as heifers, and ultimately provides evidence that the selection of feed-efficient heifer calves as replacement animals should result in a more efficient mature cow herd. This thesis provided evidence to support the selection of heifer replacements using feeding behaviours observed during a feed intake test, the use of weight monitoring technology to identify cows that may have had reproductive issues. This thesis also provided some of the first estimates of dry matter intake over the course of the production cycle in a large number of animals under normal production environments and provided estimates of the relationship between heifer and cow residual feed intake.
Download or read book Genetics of Residual Feed Intake in Beef Cattle written by and published by . This book was released on 2010 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantitative Aspects of Ruminant Digestion and Metabolism written by Jan Dijkstra and published by CABI. This book was released on 2005 with total page 734 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first edition of this book. Published in 1993, was very well received as providing a comprehensive review of the digestion and metabolism of ruminant animals. Since its publication, much new research has been conducted in the subject and knowledge has increased. This new edition includes Dr. Dijkstra as an additional editor and four completely new chapters. These cover: the gas production technique in feed evaluation; the relationship between pasture characteristics and animal performance; calorimetry; and feed processing. Other chapters have been expanded or updated as appropriate.
Download or read book Factors Affecting the Determination of Residual Feed Intake in Beef Cows Fed a Common Diet in Mid to Late Gestation written by Conor Warren and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this study were to determine residual feed intake (RFI) classification (low, medium, high) in mid to late gestation for beef cows of varying ages and breed composition fed a common diet, examine factors affecting determination of RFI, and investigate alternative models to calculate RFI. Comparisons were made among RFI classification and age groups for growth performance and measurements of body weight, body composition, and calving traits. While there were no differences in body weight, body composition, or calving traits among RFI classification groups, low RFI cows consumed less feed and had greater feed conversion than medium and high RFI cows. Intermediate aged cows gained more weight, consumed more feed, had greater feed conversion, and deposited more back fat than young and old cows. Alternate models to calculate RFI showed promise for explaining a greater proportion of variation in pregnant cow feed intake than traditional RFI models.
Download or read book Forage Fiber Analyses apparatus Reagents Procedures and Some Applications written by H. K. Goering and published by . This book was released on 1970 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
