Feeding Mixed Grass-Clover Silages with Elevated Sugar Contents to Dairy Cows

Grasses with high sugar content (WSC) have been claimed to increase feed intake and milk production and at the same time give more efficient N utilisation and thus reduce pollution (e.g. Miller et al., 2001). In an ongoing EU-supported project (“Sweetgrass”), we have grown the new varieties of perennial ryegrasses and fed them to dairy cows. Results from the first year’s experiment when pure ryegrass silages made from standard or high-sugar varieties were fed, showed small differences in feed intake, milk production and N partitioning. In order to test the principle, it was therefore decided to increase the difference in sugar content in the following experiment by mixing sucrose into the silage before feeding