The fourth edition has been completely revised with separate chapters on practical breeding of cattle, sheep and pigs. Many sections have been expanded and there is new information on horses, goats, alpacas and dogs.

1. Traits in Domestic Animals -- 2. Mendelian Principles and Laws -- 3. Principles of Population Genetics -- 4. Ways of Changing Gene Frequencies -- 5. Selection for Polygenic Traits -- 6. Aids to Selection -- 7. Selection for Multiple Objectives -- 8. Breeding Systems -- 9. Breeding in Practical Terms -- 10. Breeding Policies in Developing Regions -- 11. Breeding Schemes and Future Developments -- App. 1. Coefficient of Inbreeding -- App. 2. Coefficient of Relationship.