CHANGES IN THE NONSTRUCTURAL CARBOHYDRATES ASSOCIATED WITH THE FIELD DRYING OF OAT FORAGE

Two trials were conducted to determine the sugars, fructans and starch in oaf plants (Avena sativa L) and the changes occurring in these car bohydrate fractions during held drying in the haymaking process. The c omposition of oat herbage in non-structural carbohydrates varied marke dly between years; the contents of sugars, fructans and starch in both leaf blade and non-leaf blade materials being higher in 1990-1991 tha n in 1991-1992. Field drying produced a significant decrease (P < 0.05 ) in the amount of soluble carbohydrates. For the whole aerial plant p arts, the decline in the fructans concentration ranged between 42.8 an d 38.2% and that of sugars between 16.5 and 5.8%. The total losses of sugars and fructans in hay, expressed as losses of dry matter, ranged from 88 to 63 g kg(-1) depending on the year.