Production of high-quality milk, cheese, and other dairy products is essential to the Wisconsin dairy industry. Conventional methods to monitor dairy product quality use non-specific compositional analysis, such as fat content, or a limited number of molecules, such as lactose or lactic acid analysis. In contrast, thousands of small molecules are present in dairy products, including secondary metabolites from cows and bacterial metabolites resulting from fermentation or processing. This project will establish high-resolution mass spectrometry (HRMS) methods for analysis of small molecules in dairy products. The resulting data will be used to define small molecules that differentiate dairy products in quality. Providing analysis of this broader array of compounds in dairy will lead to a better understanding of the health benefits of dairy consumption, enable authentication of dairy processes and products, lead to discovery of new dairy quality attributes, and enable more specific monitoring of animal health.