This chapter reviews recent data upon the potential of lactic acid bacteria (LAB) to improve animal productions, and animal health and well-being. The most important expected benefits of probiotic LAB are growth-promoting effects through better feed utilization and digestion, and biological control of pathogen colonization. They are also used to enhance milk and egg production. According to their functions and properties, additives for animal feed are classified in one or several categories including technological, sensorial, nutritional, or zootechnical additives. In Europe, the authorization of microorganisms used as zootechnical additives for feed is subjected to strict regulation. The chapter addresses the main animal production sectors, their specificities in terms of the production types (meat, milk, egg), the ecosystems to be considered (gut, vaginal, and/or mammary) and presence of LAB therein, the main diseases encountered, and the use of probiotics to prevent these diseases or enhance productivity.