The dairy sector plays a vital role in global food security, with diverse livestock species contributing to milk production. This chapter examines the structure and current status of the dairy industry across different species, focusing on production levels, predominant breeds, milk collection and processing systems, as well as the challenges and opportunities for sectoral development. Milk production varies significantly by species, with cattle being the primary source globally, followed by goats, sheep, buffalo, and, to a lesser extent, camels. Foreign specialized dairy breeds such as Holstein-Friesian and Jersey dominate cattle production, while Saanen and Alpine are preferred for goat dairy systems. Milk production by local livestock animals remain low but these animal show very interesting performances of adaptability to harsh breeding condition and traditional breeding systems. Milk collection and processing systems range from informal, small-scale operations in rural areas to highly mechanized industrial facilities in developed regions. Cold chain infrastructure, pasteurization, and value-added product development enhance milk safety and marketability. The sector faces challenges such as disease outbreaks, feed shortages, climate change, and market access constraints. However, opportunities exist in technological advancements, genetic improvement, and growing consumer demand for dairy products. Strengthening cooperative networks, improving infrastructure, and adopting sustainable practices can drive further growth in the dairy industry.