Wattiaux’s project will use in-dwelling loggers to continuously record important aspects of rumen conditions, such as pH and temperature. Although UW—Madison researchers routinely assess these rumen variables at intervals, the university lacks capacity to monitor them continuously. The proposed rumen loggers will record detailed information about rumen conditions automatically and continuously for up to 45 days after insertion. Because it can produce high-resolution data with low inputs on critical rumen physiological parameters, this equipment will streamline data collection and open new areas of research. This equipment can be used to: (1) analyze daily and sub-daily variation in rumen conditions contributing to differences in lactating cows’ nitrogen efficiency, (2) improve predictive models of whole-body amino acid metabolism, (3) study feed and forage preservation methods affecting starch and fiber utilization, and (4) characterize diet, host, and microbiome interactions underlying cow health and productive efficiency.