AN ASSESSMENT OF THE RELATIVE IMPORTANCE OF SPECIFIC TRAITS FOR THE GENETIC-IMPROVEMENT OF NUTRITIVE-VALUE IN DAIRY PASTURE

There have been few successful programmes to select forage plants with improved nutritive value for dairy cattle, despite the implications o f improved forage quality for dairy production. Part of this lack of p rogress has been attributed to differences in opinion on the relative importance of improving individual traits relating to nutritive value. This paper reports the use of the Delphi survey technique to obtain a n estimate of the priority for improvement of individual nutritive val ue traits among a large group of respondents. The Delphi technique has been used previously to rank nutritive value traits in forages for li veweight gain and wool production (Wheeler and Corbett, 1989, Grass an d Forage Science, 34, 77-83). Increasing dry-matter digestibility (DMD ) was ranked as the most important goal for grasses; increased non-str uctural carbohydrate (WSC) and improved rate of digestion were ranked second and third in importance. The absence of anti-quality factors, a nd an 'optimal ratio' of rumen degradable protein to undegradable prot ein (RDP/UDP) were ranked most highly for legumes, with increased DMD and WSC following closely behind. Increased magnesium and increased li pid content were ranked lowest for both grasses and legumes. Similar r ankings were achieved when mean rankings from Australian and New Zeala nd scientists were compared with those from US and European scientists . Rankings were also similar when results from nutrition scientists we re compared with those from plant breeders/agronomists.