Présentation de l'éditeur : 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 applications. Contents: 1. Introduction. 1.1. Background and objectives. 1.2. Animal-based monitoring. 1.3. A selection of parameters. 1.4. Organization of the handbook. 2. Grouping demographic data. 2.1. Cohort splitting. 2.2. Pseudo-cohort splitting. 3. Mortality and offtake rates. 3.1. One type of removal. 3.2. Case with two types of removal. 3.3. Additional points. 4. Other demographic rates. 4.1. Reproduction rates. 4.2. Synthetic rates. 4.3. Global demographic rates. 5. Package Laserdemog. 5.1. R software. 5.2. Functions i