단파 및 혼파초지에서 Orchargrass ( Dactylis glomerata L. ) 품종의 방목반응 II. 목초이용율 , 일반성분함량 및 식생구조 변화 ( Response of Orchargrass ( Dactylis glomerata L. ) Vatieties to Grazing Monocultures and Mixed Pastires II. Changes of herbage utili

This experiment was conducted to find out the response of orchardgrass (Dactylis glorneruta L.) varieties to grazing at the condition of monocultures and mixed pastures on the field of Livestock Experiment Station at Suwon from Sep. 1989 to Oct. 1991. The varieties of orchardgrass used in this experiment were Potomac, Hallmark and Syn. No. 2 as a early maturing type, and Lidacta, Rancho and Syn. No. 10 as a late maturing type. The results obtained were as follows: 1. Herbage utilization of mixture with Hallmark variety(T2) was the highest as 78.2% and that with Rancho variety(T5) was the lowest as 70.2%. but there was no difference(P>0.05). Mixtures with early maturing varieties(T1, T2 and T3) were higher as 77.4% than those with late varieties(T4, T5 and T6) as 72.9% in herbage utilization. In monocultures Rancho variety(T5) was the highest as 68.6% and Lidacta variety(T4) was the lowest as 58.8%, and mixtures with early maturing varieties(T1, T2 and T3) as 66.6% were higher than those of late(T1, 72 and 73) as 64.6%. 2. The content of crude protein of 6 mixed pastures ranged from 19.7% to 22.8%, and those of ether extracts, crude fiber, crude ash and nitrogen free extract were 6.6 to 7.5%, 24.9 to 26.2'76, 1 1.5 to 1 1.9% and 33.6-35.4 8, respectively, But there were not different significantly(P>0.05). In monocultures, significant difference by variety was observed in crude protein content(P<0.05). 3. In botanical composition, there was just a little different among 6 mixtures, having 90% or more in grass percentage. The percentages of each orchardgrass varieties were decreased, but those of perennial ryegrasses were increased as grazing sesson was progressed in all treatment.