Download or read book Evaluating Residual Feed Intake in Replacement Heifer Calves for Correlation with Breed and Sire written by Ashley Diane Wright and published by . This book was released on 2014 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: With feed costs representing on average 65% of the total cost of production improvements in feed efficiency could have a major impact on the beef industry. Postweaning performance and feed efficiency data were collected on 114 heifers born on the University of Arizona's V bar V Ranch. Residual feed intake (RFI) was significantly correlated with dry matter intake (DMI) (r = 0.46) and G:F (r = -0.43), while G:F was moderately correlated with initial age (r = -0.54), initial body weight (r = -0.40), and average daily gain (ADG) (r = 0.68). Residual gain (RG) was moderately correlated with RFI (r = -0.41) and highly correlated with ADG (0.62) and G:F (0.73). In addition, RG was significantly correlated (r = -0.21) with initial weight suggesting that selection for RG could lead to increased cow mature size. Heifers were sorted into three breed categories: Hereford, Hereford cross, and Wagyu cross and breed effect on performance and feed efficiency traits were analyzed. Significant differences in DMI, FCR, and RG were noted, but likely due to significant differences in age at the time of testing. RFI was not significantly different between breed groups, suggesting that RFI is less influenced by animal age than other measures of feed efficiency. In addition, sires of study heifers with 5 or more progeny were selected and progeny performance and feed efficiency traits were compared between sires. No significant differences in ADG, RFI, FCR, or RG were noted between sire progeny. This was likely due to an insufficient number of progeny used in the trial. Further research and an increased number of animals used may uncover significant impacts of sire on RFI.
Download or read book The Assessment of Replacement Heifer Production Efficiencies Through Residual Feed Intake and Key Hormone Profiles written by Brock Andrew Smith and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Residual Feed Intake in Beef Cattle in Relation to Breed Selection and Behavior written by Marcus McGee and published by . This book was released on 2014 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Feed efficiency is a necessary factor in beef production systems due to rising feed ingredient costs, population growth, and beef supply demands. With this known, it is important for researchers to delve into mechanisms involved in efficiency to provide producers with a knowledge base for future selection and breeding programs. Though the use of residual feed intake (RFI) is fairly well know, traditional traits are often considered more desirable due to costs associated with testing. However, previous research has provided evidence of benefits using a less biased measurement (RFI) in comparison with its counterparts (e.g. ADG, FCR, F:G etc.) Though RFI does provide indication of efficiency status, there are underlying mechanisms that also play a role in these measurements that are not completely understood. One attribute of efficiency often overlooked is feeding behavior, in which this body of work attempts to interpret via relationships with RFI. Previous research has provided has examined relationships between these two parameters, however further studies are necessary to gain a more solid foundation. Research within this dissertation will add to this knowledge base using two breeds of cattle examined for behavior traits (bunk visit frequency, bunk visit duration, feed bout frequency, feed bout duration, meal frequency, meal duration, and average meal intake) during the course of RFI evaluation. Niche breeds of beef cattle (e.g. Japanese Black Cattle) are often excluded from feed efficiency examinations, due to focuses of output, carcass quality traits, and increased specialty market value. However, the recent rise of feed ingredient costs are universal, and producers of niche breeds may benefit as well. Within this body of work, 3 cohorts of Wagyu cattle were evaluated for feeding behavior parameters with some insight towards relationships with efficiency. Red Angus cattle were also evaluated over both growing and finishing phase RFI to clarify feeding behaviors' role in efficiency. Results from these studies provide researchers with additional tools for elucidating these relationships as well as identifying specific feeding behaviors that contribute to efficiency status in beef cattle.
Download or read book Examining Mechanisms Contributing to the Biological Variation of Residual Feed Intake in Growing Heifers and Bulls and in Mid gestation Females written by Aimee Hafla and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this study were to characterize residual feed intake (RFI) in growing bulls and heifers and in mid-gestation females to examine relationships with performance, body composition, feeding behavior, digestibility (DMD) and heart rate (HR) and evaluate the impact of RFI on bull fertility and cow forage utilization. Additionally, use of the n-alkane method to predict individual animal variations in intake was investigated. To accomplish these objectives, multiple RFI studies were conducted. In all studies RFI was computed as the difference between actual and expected DMI from linear regression of DMI on mid-test metabolic BW and ADG. To evaluate phenotypic relationships between feed efficiency, scrotal circumference (SC) and semen-quality an experiment was conducted with yearling bulls (N=204). Residual feed intake was not correlated with BW and ADG, but was positively associated with 12th-rib back fat (BF) such that the more efficient bulls were leaner. Bulls with low RFI had similar SC and progressive motility of sperm compared to high-RFI bulls. However percent normal sperm were weakly associated with RFI in a negative manner. To examine phenotypic relationships between heifer postweaning RFI, and performance, efficiency, HR, and DMD of mid-gestation cows, RFI was measured in growing Bonsmara heifers (N=175). Forty-eight heifers with divergent RFI were retained for breeding. Subsequently, intake, performance and feeding behavior was measured on mid-gestation females. Pregnant females classified as having low postweaning RFI continued to consume 22% less feed, spent 25% less time eating, and had 7% lower HR while maintaining similar BW, ADG and body composition compared to high RFI females. A moderate association between RFI in growing heifers and subsequent efficiency of forage utilization in pregnant cows was found. Growing heifers identified as efficient had greater DMD, however DMD in mature cows was similar between RFI groups. The n-alkane method of predicting intake detected differences in intake between divergent RFI groups in mid-gestation females. Results from this study indicate that inclusion of RFI as a component of a multi-trait selection program will improve feed efficiency of growing animals and mid-gestation females with minimal impacts on growth, body composition, and fertility traits.
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 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 Australian Journal of Agricultural Research written by and published by . This book was released on 2003 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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:
Download or read book Guidelines for Uniform Beef Improvement Programs written by Dixon D. Hubbard and published by . This book was released on 1981 with total page 84 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 2012-06-18 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 Proceedings written by Beef Improvement Federation. Research Symposium & Annual Meeting and published by . This book was released on 2006 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agrindex written by and published by . This book was released on 1995 with total page 1088 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Breeding for Robustness in Cattle written by Marija Klopčič and published by Brill Wageningen Academic. This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The past decade has revealed unfavourable trends in e.g. fertility, udder health and locomotion in some major dairy cattle breeds due to a large increase in production and insufficient consideration of functional traits in the breeding goals. Such unfavourable trends in some functional traits increase costs. Additionally, the enlargement of herds leads to less available labour time per individual cow. This asks for cows that are easy to handle. At the same time, society is demanding a higher welfare standard of animals. These contradicting developments have increased the desire for so called more robust animals. Robustness can be defined as 'the ability to maintain homeostasis in commonly accepted and sustainable herds of the near future'; or 'the ability of the cow to function well in the environment she lives in as well as in a wide range of climates and production systems'. This book contains a series of articles (26) dealing with the concept of robustness, including aspects like evolution, genetics, environment, animal health and welfare, and integrity. Besides the major functional traits also the links to energy balance, hot climatic conditions, and the attitude and input of stakeholders towards robustness as part of the breeding program are discussed. This book is the first attempt to summarise the available knowledge concerning this topic in cattle, making this book unique. The contributions are from authors of 16 countries from all over the world. However, the focus is presently on farm animal level, while in future robustness of the whole production system may also require additional attention.
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 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 Tables of Composition and Nutritional Value of Feed Materials written by Institut national de la recherche agronomique (France) and published by . This book was released on 2004 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NorFor written by Harald Volden and published by Springer Science & Business Media. This book was released on 2011-10-05 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: NorFor is a semi-mechanistic feed evaluation system for cattle, which is used by advisors in Denmark, Iceland, Norway and Sweden. This book describes in detail the system and it covers five main sections. The first is concerned with information on feed characteristics, feed analysis and feed digestion methods. The second section describes the digestion and metabolism in the gastrointestinal tract and the supply and requirement of energy and metabolizable amino acids. The third section considers the prediction of feed intake and physical structure of the diet. The fourth section focuses on model evaluation and the final section provides information on the IT solutions and feed ration formulation by a non-linear economical optimization procedure. This book will be of significant interest to researchers, students and advisors of cattle nutrition and feed evaluation.
