This 2-year project has been helpful in characterizing nonstructural carbohydrates in cool-season grasses. We have learned a lot about the normal fluctuations seen across environments and, more specifically, variations due to genetic differences. The main conclusions are: 1. Percentages of nonstructural carbohydrate are highly variable throughout the growing season and between species and varieties of cool-season forage grasses. 2. Growth rate may affect the level of TNC in cool-season forage grasses. 3. Consistently, orchard grasses contained lower levels of TNC and had higher DM yields than ryegrasses. 4. Grasses bred in Europe to emphasize nonstructural carbohydrates are higher in sugars than the average of the population found in the U.S.