CONTRIBUTION AND NUTRITIVE VALUE OF THE MAJOR PLANT COMPONENTS OF OATS THROUGH PROGRESSIVE STAGES OF DEVELOPMENT

Abstract

Two oat (Avena sativa L.) cultivars, Harmon and Sioux, and an unlicensed cultivar of Avena orientalis L., referred to as "Yorkton," were harvested at the early leaf, before boot, boot, headed, early bloom, late bloom, milk, dough, and ripe stages. Yorkton gave smaller yields than the other two cultivars at all stages after heading, but was slightly more leafy. Percent leaves by weight for all cultivars varied from near 90% in first cut to about 14% when ripe. Crude protein of leaves declined from 30 to 6% over the nine cuttings whereas that of stems went from 24 to 5%. Leaf lignin increased from 35 to 50% through the whole range of growth whereas stem lignin increased more rapidly from 45 to 70% in a shorter period of time. Leaves had 20% more energy than did stems. They were also 10% more digestible as determined by in vitro digestible organic matter. As whole plant feed there was no advantage in delaying harvest beyond the milk to soft dough stage.