VOLATILES FROM FRESH AND AIR-DRIED VEGETATIVE TISSUES OF TALL FESCUE (FESTUCA-ARUNDINACEA SCHREB) - RELATIONSHIP TO CATTLE PREFERENCE

Volatiles from fresh and air-dried forage of eight tall fescue cultiva rs were collected on Tenax-TA adsorbent and then examined by gas chrom atography/mass spectrometry (GC/MS) and GC/flame ionization detector c hromatography (GG/FID). Fifty of 52 compounds emitted from fresh forag e and 99 of 103 emitted from hay were identified. The same compounds w ere common to all cultivars, and quantitative differences, within fres h forage or hay, were not dramatic. Fresh forage yielded 12-32 mu g/L of volatiles, while dry forage yielded 0.18-0.47 mu g/L. (Z)-S-Hexenyl acetate made up 82% of total emissions from fresh forage but only 0.2 4% from hay. Green-leaf odor compounds made up 11% in fresh forage and 6% in hay. Previously determined grazing preferences by cattle were r elated positively to 6-methyl-5-hepten-2-one and negatively to (Z)-3-h exenyl propionate and acetic acid, which together made up <0.2% of vol atiles from fresh forage.