• Asian-Australasian Journal of Animal Sciences
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• 제18권12호
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• pp.1727-1734
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• 2005

The fermentation characteristics and mono- and di-saccharides compositions during the early stage of ensiling were studied with a temperate grass, Italian ryegrass (Lolium multiflorum Lam.) and a tropical grass, guineagrass (Panicum maximum Jacq.). The laboratory silos were kept in the room set at 25$^{\circ}C$, and then were opened on 0.5, 1, 2, 3, 5 and 7 days (14 days in Italian ryegrass) after ensiling, respectively. The Italian ryegrass silage showed a fast and large pH decrease caused by a fast and large production of lactic acid during the first 5 days of ensiling and succeeded to achieve lactic acid type fermentation; high lactic acid/acetic acid and lactic acid content at the end of ensiling (14 days), low values of pH (3.74), acetic acid, ethanol and ammonia-N/total nitrogen, none or only small amounts of Butyric acid, valeric acid and propionic acid. The guineagrass silage showed a slow decrease in pH and a slow increase in lactic acid content during the full ensiling period, causing a high final pH value, low contents of lactic acid, acetic acid, total volatile fatty acids and total organic acids. In Italian ryegrass silage, mono- and di-saccharides compositions decreased largely within the initial 0.5 day (12 h) of ensiling. Sucrose disappeared rapidly within the initial 0.5 day of ensiling, but fructose and glucose contents showed an initial rise by the activity of enzymes in plant tissues, and then decreased gradually. On the other hand, the contents of monoand di-saccharides in guineagrass showed the largest decreases due mainly to plant respiration within the initial 0.5 day of ensiling, and no initial rises in fructose and glucose contents during the early stage of ensiling because of the absence of fructans which are hydrolyzed into fructose and glucose in temperate grasses. In both silages, the rate of reduction in mono- and di-saccharides compositions within the initial 5 days of ensiling was ranked in the order of glucose>fructose>sucrose, suggesting that glucose and fructose might be more favorably utilized than sucrose by microorganisms and glucose is the first fermentation substrate. It was concluded that the silage made from Italian ryegrass with high moisture content had a good fermentation quality owing to the dominance of lactic acid bacteria and active lactic acid fermentation during the initial stage of ensiling. These results can be explained by rapid plant sap liberation and the high activity of plant enzyme hydrolyzed fructans into fructose and glucose within the initial 2 days of ensiling, which stimulate the homofermentative lactic acid bacteria growth. In ensiling a temperate grass, the physical characteristics may ensure the rapid onset of fermentation phase, which results from the smaller losses of water-soluble carbohydrates during the initial stage of ensiling and providing sufficient water-soluble carbohydrates for lactic acid bacteria. The silage made from guineagrass with intermediate dry matter and high initial mono- and di-saccharides content was stable silage. This could be explained by the higher incorporation of air during the very early stage of ensiling and the restriction of cell breakdown and juice release due to the properties of a tropical grass with coarse porosity and stemmy structures. These physical characteristics delayed the onset of lactic acid bacteria fermentation phase by extending the phases of respiration and aerobic microorganisms activity, causing the higher loss of water-soluble carbohydrates and the shortage of lactic acid bacteria fermentation substrates.

• 한국초지조사료학회지
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• 제29권1호
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• pp.63-72
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• 2009

본 연구에 이용될 공시시료는 2007년과 2008년에 걸쳐 채집되었으며, 기호성 조사는 2008년 6월 21일 수행하였다. 공시시료는 화본과와 두과목초(passes and legumes)류는 mixed passes, orchardgrass, tall fescue, alfalfa 및 white clover 의 5종, 야초와 잡초(native grasses 및 weeds)류는 mixed native grasses, Miscanthus sinensis Anderss, Arundinella hirta (Thunb.) Tanaka, barnyard grass 및 short awn의 5종, 사료작물과 볏짚(forage crops and straw)류는 barley +hairy vetch, wheat + hairy vetch, rye silage, barley silage 및 baled rice straw의 5종, 수염과 낙엽(browse and fallen leaves)류는 mixed browse, oriental white oak browse, Quercus serrta Thunb. oriental cherry fallen leaves 및 Japanese chestnut fallen leaves의 5종, 그리고 수입건초(imported hay and straw)류로 timothy, tall fescue hay, annual ryegrass, klinegrass 및 alfalfa의 5종 등 총 25종을 공시하였다. 공시축은 유산양(Saanen 우, 평균체중 $25{\pm}2.1kg$) 10두를 공시하였고, 시험은 유산양은 충남 금산군 추부면 유산양목장에서 수행하였다. CP, NDF, ADF, hemicellulose, cellulose, lignin 함량및 IVDMD는 채취장소, 초종, 생육단계 및 예취시기에 따라 조사료원별로 차이를 나타내었다(p<0.05). 유산양은 혼합목초(mixed grasses) 와 두과목초인 화이트 클로버(white clover)나알팔파(alfalfa) 등을 즐겨 채식하였으나, 콘포볏짚(baled rice straw)이나 호밀 사일리지 (rye silage) 등은 거의 채식하지 않았다. 유산양이 즐겨 채식한 조사료원은 NDF나 ADF와 같은 섬유소물질의 함량이 낮은 반면에 IVDMD는 높은 조사료를 주로 선택하여 채식하는 습성을 나타내었다(p<0.05). 유산양(Saanen)은 화본과 와 두과목초(34.6%)를 가장 즐겨 채식하였던 것으로 보아 초류채식형 (grazers)에 가까운 것을 재확인하였다.