Identification of Feed Intake Traits Related to Beef Reproductive Improvement PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Identification of Feed Intake Traits Related to Beef Reproductive Improvement PDF full book. Access full book title Identification of Feed Intake Traits Related to Beef Reproductive Improvement by Cameron Alexander Olson. Download full books in PDF and EPUB format.
Author: Cameron Alexander Olson Publisher: ISBN: Category : Beef cattle Languages : en Pages : 0
Book Description
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.
Author: Cameron Alexander Olson Publisher: ISBN: Category : Beef cattle Languages : en Pages : 0
Book Description
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.
Author: Nicholas Oliver Minton Publisher: ISBN: Category : Beef cattle Languages : en Pages : 118
Book Description
Selecting beef cattle which metabolically are more efficient at converting feed into gain or body weight maintenance is one way to reduce feed cost in beef production. Residual feed intake (RFI) is one trait used to identify animals which are metabolically feed efficient or inefficient. Trials in the current study investigated whether animal RFI varies between trials conducted at two different stages of maturity and the influence on progeny feed efficiency when sires and dams of known RFI phenotypes are mated. We further investigated whether RFI measured postweaning or later in maturity more accurately predicted progeny feed efficiency in addition to whether ribeye area and body composition varied between steers from either RFI- or RFI+ dams. Reranking in RFI of animals did occur between trials, however; RFI phenotype was correlated (rp = 0.54; P [lesser than] 0.01) between postweaning and mature trials indicating animals identified as feed efficient or inefficient remain feed efficient or inefficient further into maturity. More efficiently mated RFI- sires and dams produced heifer and steer progeny with higher feed efficiencies (P [lesser than] 0.05; P [lesser than] 0.10, respectively) with no difference in average daily gain (P = 0.52) in comparison to progeny from RFI+ sires and dams. Postweaning dam RFI phenotype showed stronger correlations to progeny RFI phenotype (rp = 0.60; P [lesser than] 0.05) while steers from RFI- dams tended (P [lesser than] 0.10) to have larger developments in ribeye area with no variation (P [greater than] 0.10) in body composition to steers from RFI+ dams. Selection upon RFI is an accurate trait to select upon to improve herd feed efficiency as well as increase profitability in beef production.
Author: Marcus McGee Publisher: ISBN: Category : Beef cattle Languages : en Pages : 310
Book Description
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.
Author: Rodney A. Hill Publisher: John Wiley & Sons ISBN: 0470959525 Category : Science Languages : en Pages : 328
Book Description
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.
Author: Michael Patrick Davis Publisher: ISBN: Category : Beef cattle Languages : en Pages : 90
Book Description
Residual feed intake (RFI) is the difference between measured feed intake and predicted feed intake of an animal. Intake prediction is computed from a regression of intake on gain and metabolic body weight. Residual feed intake is used as a measure of metabolic efficiency. As RFI increases, feed intake (FI) and feed conversion ratio (FCR) increase with no change in postweaning growth and body weight in steers. Identification and selection for lower RFI cattle would improve herd feed efficiency without influencing growth. Steer residual feed intake measured in the growing phase, is related to residual feed intake during the finishing phase. Animals with low residual feed intake in the growing phase had lower residual feed intake and improved feed efficiency in the finishing phase. Serum concentrations of glucose and mitochondrial function are related to metabolic efficiency and may differ between residual feed intake phenotypes. Serum concentrations of glucose at weaning were greater (P [lesser than] 0.05) in low (efficient) compared to high (inefficient) RFI steers. Mitochondrial complex protein concentrations I:II and I:III ratios were greater (P [lesser than] 0.05) in low extreme versus high extreme RFI steers. Diets varied in rumen undegradable protein content were used to determine impact of intestinal amino acid supply on growth performance. Increasing rumen bypass amino acids in no roughage diets during the growing phase tended (P [lesser than] 0.15) to influence ADG and FCR in the growing phase such that as rumen bypass amino acid level increased growth and feed efficiency improved in the growing phase. Steers fed post ruminal absorbable amino acid levels below that required for growth in growing phase tended (P [lesser than] 0.15) to have improved feed efficiency in the finishing phase. Also, during the growing phase as bypass amino acids increased subcutaneous and intramuscular fat deposition decreased in steers during the finishing phase. Feeding a level of bypass amino acids below optimum for growth to steers during the growing phase decreased (P [lesser than] 0.05) longissimus dorsi muscle area in steers during the finishing phase.
Author: Colin G. Scanes Publisher: CRC Press ISBN: 1351648136 Category : Nature Languages : en Pages : 509
Book Description
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.
Author: J. France Publisher: CABI ISBN: 1845933591 Category : Technology & Engineering Languages : en Pages : 590
Book Description
Mathematical modelling is increasingly applicable to the practical sciences. Here, mathematical approaches are applied to the study of mechanisms of digestion and metabolism in primary animal species. It also explores common themes between species, and provides an integrated approach to mathematical modelling in animal nutrition.
Author: Cameron Alexander Olson
Author: Cameron Alexander Olson
Author: Nicholas Oliver Minton
Author: Marcus McGee
Author: Rodney A. Hill
Author: Michael Patrick Davis
Author: Colin G. Scanes
Author: Dixon D. Hubbard
Author: J. N. Wiltbank
Author: Mudasir Ahmad Syed
Author: J. France