This chapter reviews advances in understanding carbohydrate requirements and utilization in dairy cattle. The chapter begins by first describing the importance of feed analysis, focusing specifically on fiber analysis. It then moves on to discuss detergent fibers, which is then followed by an analysis of neutral detergent-soluble carbohydrates. A section on rumen carbohydrate and protein interactions is also provided, which is then followed by sections on rumen health and the importance of higher forage diets. The chapter also provides case studies that provide examples of using higher forage rations in dairy cows. Current on-farm analysis tools are also described, which is then followed by a section on the use of nutrition models.