Information on an animal and its relatives can be used to predict the animal's genetic merit, taking account of the relationships between measurements and the economic values of traits. This book describes the methodology for predicting the genetic merit of animals in the context of improvement in an animal program. It discusses the methods for combing different sources of information and illustrates their use with examples of breeding programs in cattle, sheep, pigs, and poultry. This methodology is developed from first principles, without unnecessary detail or complexity, and all the required statistical and mathematical concepts are fully explained. A series of questions helps reinforce the ideas and provide some practical experience in the prediction of genetic merit. The text is most useful for final year undergraduate and first-year graduate students of quantitative genetics and animal breeding.