Water‐soluble carbohydrates in perennial ryegrass breeding

Perennial ryegrasses showing genetic differences in water‐soluble carbohydrate content (WSC) were assessed for dry matter digestibility (DMD), crude protein (CP) and dry matter production (DM) in both spaced plant and small plot trials. Among 100 accessions grown as spaced plants there appeared to be more genetic variation for WSC than for DMD or CP. In both spaced plants and plots, WSC was consistently positively correlated with DMD, negatively correlated with CP and showed little correlation with DM. Correlations between CP and DMD were rather inconsistent and some negative correlations were obtained between CP and DM, suggesting that environmental effects, particularly with regard to nitrogen availability, affected CP more than WSC content. It was concluded that there is considerable potential for using ryegrasses with high WSC contents to develop varieties with improved feeding value without sacrificing production.