Improving the available energy in natural fodders is the most desirable way of increasing the nitrogen
use efficiency of livestock production. Perennial ryegrass (Lolium perenne) shows considerable genetic variation
for carbohydrate content. Most of the carbohydrate is water-soluble, but starch is also present in vegetative tissues
and is useful because it is readily available in the rumen and persists during ensiling. The relationships between
fructan and starch accumulation in ryegrass can be genetically dissected by QTL analysis. QTL for fructan and
starch do not overlap, so starch and fructan may be independently selectable. Groups of genotypes from a mapping
family were polycrossed in 2002 to produce marker selection lines for further research.