With the exception of maize, very little research has been conducted in annual forages for the improvement of forage quality. The objectives of this research are to: (1) To determine if forage quality characteristics vary among barley genotypes, (2) To determine if there are quantitative trait loci (QTL) associated forage quality traits in barley, (3) To determine if variation in forage quality characteristics among barley lines are heritable. A 6-rowed barley population of Lewis x Karl RIL lines was used to identify quantitative trait loci (QTL) for forage quality traits in barley. The 146 lines were grown in a randomized complete block field trial (r = 2) under dryland conditions. Forage samples were collected at plant anthesis and at peak forage yield. Dry matter forage yield (FY) was determined. In situ DM digestibility (ISDMD) at 48 h was determined. A sub-sample of each line was evaluated for NDF, ADF, N, and NO3-N. Substantial genetic variation in forage quality traits was present in the 146 Lewis x Karl RIL barley population. Moderate levels of heritability were seen for NO3-N and ISDMD were seen at the peak forage yield stage of maturity (h2 = 52 and 55 %, respectively). This study indicated that QTL models explained about 41%, of total phenotypic variation explained by the model in NO3-N concentration. Two QTLs controlling variation in NO3-N content were detected on chromosomes 3H and 6H. These QTLs explained approximately 13.5 and 27.3 % of the variation explained by the QTL, respectively. If selections were made at the anthesis stage of plant maturity for improved ISDMD subsequently there would be an increase NO3-N, which would be undesirable. Selection for improved ISDMD at peak forage yield may not lead to increased NO3-N levels. It would be advantageous to make selections based on peak forage yield values.