Book excerpt: This book summarizes the development and statistical validation of a guinea pig model as an alternative for potency testing of the viral antigens included in combined vaccines applied in cattle to control the respiratory, reproductive, and neonatal calf diarrhea syndromes. The model allows, in one serum sample, to test the vaccine quality for all the viral antigens included in aqueous as well as in oil-adjuvanted formulations of bovine vaccines. The methodology proposed for the control of bovine herpes virus, parainfluenza, and rotavirus were recommended by CAMEVET as guidelines for the 30 countries in the forum, including the US. Key Features Reviews combined vaccines used for cattle Summarizes animal models used for vaccine testing Focuses on bovine herpesviruses, rotaviruses, parainfluenza, and bovine viral diarrhea virus Provides guidance on the effectiveness of the Guinea Pig model for testing vaccine immunogenicity