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Calculation of Demographic Parameters in Tropical Livestock Herds : A discrete time approach with LASER animal-based monitoring data / by Matthieu Lesnoff, Renaud Lancelot, Charles-Henri Moulin, Samir Messad, Xavier Juanès, Christian Sahut
Contributor(s): Resource type: Ressourcentyp: Buch (Online)Book (Online)Language: English Series: SpringerLink BücherPublisher: Dordrecht ; s.l. : Springer Netherlands, 2014Description: Online-Ressource (X, 99 p. 33 illus., 23 illus. in color, online resource)ISBN:- 9789401790260
- 590
- QL1-991
Contents:
Summary: Ruminant livestock (cattle, small ruminants, and camels) have a determinant economic role in many tropical developing countries. In traditional low-input farming systems, demographic parameters (e.g. reproduction or mortality rates) are important indicators for estimating and modelling herd dynamics and production, and impacts of farming practices or environmental risks (droughts, epizootics, etc.). Although such parameters have been extensively described in the literature on tropical livestock, many descriptions only rely on empirical presentations of formulas without clear methodological justifications. This book fills this gap, presenting the main concepts used to define and compute demographic parameters for tropical livestock, such as probabilities and hazard rates of occurrences and competing risks. It is based on the LASER software, a relational database management system specifically designed for animal-based monitoring surveys. It also provides an introduction on R, the free statistical software (http://www.r-project.org) used for the computations. It is intended for researchers, engineers, technicians, or students dealing with demographic parameters of tropical ruminant livestock in various fields such as animal science, epidemiology, or economy. It will also be valuable for readers wishing to enhance their understanding of definitions and formulas found in the literature, and it will guide them in their applicationsPPN: PPN: 1657883558Package identifier: Produktsigel: ZDB-2-SBL
Foreword; Acknowledgements; Contents; Chapter 1: Introduction; 1.1 Background and Objectives; 1.2 Animal-Based Monitoring; 1.3 A Selection of Parameters; 1.4 Organization of the Handbook; Chapter 2: Grouping Demographic Data; 2.1 Cohort Splitting; 2.1.1 Horizontal and Vertical Cells; 2.1.2 Aggregation of Cells; 2.2 Pseudo-cohort Splitting; 2.2.1 Columns of Cells; 2.2.2 Other Types of Cells; Chapter 3: Mortality and Offtake Rates; 3.1 One Type of Removal; 3.1.1 Probabilistic Models; Rate p; Rate h; Inferences; 3.1.2 Calculations Over Subperiods; Rate p; Rate h; Relations Between p and h
3.1.3 Mean Size Approximation3.2 Case with Two Types of Removal; 3.2.1 Crude Probabilities; 3.2.2 Hazard Rates; 3.2.3 Relations Between Crude Probabilities and Hazard Rates; 3.2.4 Competing Risks and Interferences; Competing Risks; Hypotheses for Competing Risks; Interferences Between Mortality and Offtake Rates; 3.2.5 Corrected Probability of Death; Approach 1; Approach 2; Approach 3; Synthesis of the Mortality Estimates; 3.3 Additional Points; 3.3.1 Calculations with Intake; 3.3.2 Non-constant Rates; 3.3.3 Case with More Than Two Types of Events; Chapter 4: Other Demographic Rates
4.1 Reproduction Rates4.1.1 Parturition and Abortion Rates; Constant Rates; Reproductive Females; Seasonal Variations and Consequences for Annual Estimates; Remark on the Mean Parturition Interval; 4.1.2 Prolificacy, Stillbirth and Female-at-Birth Rates; 4.2 Synthetic Rates; 4.3 Global Demographic Rates; 4.3.1 Herd Dynamics; 4.3.2 Production; Chapter 5: Package Laserdemog; 5.1 R Software; 5.2 Functions in Laserdemog; 5.2.1 Data Importation; 5.2.2 Data Splitting; 5.2.3 Calculation of the Parameters; 5.3 Additional Points; 5.3.1 Arguments ini and end; 5.3.2 Codes for Exits and Entries
Argument eventTypes of Natural Deaths and Slaughtering; 5.3.3 Global Dynamics and Production Rates; Dynamics Rates; Production Rates; Recommendations for amr and prodn; Chapter 6: Numerical Examples; 6.1 Example 1 - Overall Description; 6.1.1 Data Importation and Splitting; 6.1.2 Herd Sizes and Structures; Herd Sizes; Herd Structures; 6.1.3 Demographic Rates; Mortality; Offtake and Intake; Parturition; Abortion; Prolificacy; Stillbirth; Females at Birth; Global Rates; 6.2 Example 2 - More on Reproduction Rates; 6.3 Example 3 - Test of a Treatment on Mortality
6.3.1 Data Importation and Splitting6.3.2 Descriptive Analysis of the Treatment Effect; 6.3.3 Test of the Treatment Effect; Corrected Probability; Hazard Rate; Chapter 7: Annexes; 7.1 Rates p and h in Survival Analyses; 7.1.1 One Cause of Removal; 7.1.2 Two Causes of Removal; 7.2 R Materials; 7.3 Structure of Tables Generated by hsplit and vsplit; References
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