산지초지 개량전과 후의 채식초류 이용에 관한 연구 = A Study on the Utilization of Herbage Diets Before and After Improvement of Hill - Pasture

다국어 초록 (Multilingual Abstract)

Monthly changes in botanical composition, preference index, dry matter(DM) production, DM intake, chemical composition, in uitro DM digestibility(IVDMD), herbage utilization percentage, and chewing efficiency of dietary herbage samples from sheep fitted esophageal fistula and fecal collection bag were compared between native and improved grasslands. Experimental field was situated in Chungnam National University, Daejon and treated by one plot design from July, 1987 to July, 1989. The results obtained are summarized as follows ; 1. Miscanthus sinensis, Arundinella hirta, and Phragmites communis dominated and the botanical composition of the plants summed up to 68∼86% on native grassland and Dactylis glomerata dominated and summed up to 54∼68% on improved grassland. The botanical composition of annuals such as Setaria viridis and Digitaria sanguninalis slightly increased on native grassland during the summer, but on improved grassland the composition of Festuca arundinacea and Trifolium repens relatively increased. The botanical composition of highly preferred native species on native grassland markedly decreased than forage species on improved grassland as the season progressed. 2. Miscanthus sinensis, Arundinella hirta, and Phragmites communis were less preferred native species and Carex lanceolata, Carex siderosticta, Festuca ouina, and Commelina communis were unpalatable species in all season, while Digitaria sanguinalis, Setaria uiridis, Erigeron canadensis, Rubus crataegifolius, Lespedeza bicolor, and Robinia pseudo-acasia were highly preferred among native grassland vegetation. Forage species on improved grassland generally were preferred than native species and there was no difference in preference indices among improved grassland vegetations. Trifolium repens and Lolium perenne were the highly preferred species. 3. The highest plant height and leaf area index(LAI) on native grassland were observed in July and August on native grassland, but those on improved grassland was obtained in May and June. Average plant height and LAI on improved grassland were markedly higher than those on native grassland(p $lt;0.01). 4. About 58.8% of annual DM production(3295kg/ha) on native grassland was produced during the summer (July and August), while about 65.7% of annual DM production(0449kg/ha) on improved grassland was produced during the spring(April, May and June). Total DM production on improved grassland was markedly higher than the DM production on native grassland(p $lt;0.01). The maximum DM production per day on native grassland was observed in July(34.6kg/ha/day), while on improved grassland was observed in May(100.4kg/ha/day). Averaged DM production per day on improved grassland was about 45.6kg per ha, while that on native grassland was about 15.1kg per ha(p $lt;0.01). 5. Fodder value on improved grassland was about 7.08 in average, while the value on native grassland was about 3.08 in average(p $lt;0.01). 6. The percentage of herbage utilization on native grassland was about 56.5% in average, while the percentage on improved grassland was about 78.1% in average(p $lt;0.01). 7. Grazing capacity on native grassland was about 121 cow-day per ha in average, while the capacity on improved grassland was about 544 cow-day per ha(p $lt;0.01). 8. Contents of crude protein(CP), crude ash(CA) and IVDMD of collected herbage samples from esophageal fistulated sheep grazed on both native and improved grasslands were higher than those of offered and residued herbage samples, While the contents of crude fiber(CF), neutral detergent fiber(NDF), acid detergent fiber (ADF) of collected herbage samples were lower than those of offered and residued samples(p $lt;0.01). 9. Contents of CP and IVDMD of herbage samples on improved grassland were higher than those on native grassland, while contents of CF, NDF and ADF were lower than those on native grassland(p $lt;0.01). Contents of CP and IVDMD of herbage samples on native grassland