Effects of Nitrogen Fertilization Levels and Some Additives on the Chemical Composition and Silage Quality of Forage Rape (Brassica napus Subsp. oleifera) I. Effects of harvestinh dates and N forage rape

질소시비수준과 첨가제가 사초용 유채의 사료가치 및 사일리지의 품질에 미치는 영향 I. 예취시기 및 질소시비수준이 수량 및 사료가치에 미치는 영향

Insufficient herbage during the fall in the temperate areas of the world has been a serious limitation in animal production, but leafy brassicae are potentially very useful for extending the grazing season when the growth and quality of grass is poor. This study was conducted to determine the effects of cutting stage and N fertilization on dry matter (DM) yield, forage quality and chemical composition of forage rape (Brassica napus Subsp. oleifera). The experiment was conducted in the Experimental Livestock Farm of Seoul Nat'l Univ., at Suweon, during 1985- 1986. The results obtained are summarized as follows: 1. DM percentage and yield significantly increased as the growth period was prolonged and decreased as the N fertilization increased, but in-vitro dry matter digestibility (IVDMD) was unaffected by the treatments. 2. Plant height, DM yield and $NO_3$-N content significantly increased as the rate of N fertilization increased and DM percentage decreased, but the IVDMD was unaffected. 3. The forage rape had high percentage of crude protein and ash. Glutamic acid, pro!ine and aspartic acid were the major amino acids. Concentration of P, Ca and Mg were high.