Comparison of Digestibility, Metabolizable Energy and Anatomy between Nilegrass andPangolagrass at Different Growth Stages

尼羅草及盤固草不同生長期之消化率、代謝能及組織之比較

林正斌(Jeng-Bin Lin) ； 李美珠(Mei-Ju Lee) ； 張世融(Shyh-Rong Chang) ； 許福星(Fu-Hsing Hsu)

《台灣農學會報》 12卷6期 (2011/12) Pp. 500-512

https://doi.org/10.6730/JAAT.201112_12(6).0001

摘要

尼羅草（Acrocras macrum Stapf）和盤固草（Digitaria decumbens Stent）分別是多年生C3和C4型植物，此二牧草品種在台灣具高產量及割後快速再生的特性。這個研究主要是針對此二牧草品種，在春、秋二季割後的4、6、8 及10週進行植物體之化學成分、代謝能（Metabolizable energy,ME）、酸洗纖維（Acid detergent fiber,ADF）、中洗纖維（Neutral detergent fiber, NDF）、水溶性碳水化合物（Water soluble carbohydrate, WSC）及在牛瘤胃中植物體細胞壁被分解之比較。在春、秋二季尼羅草之ADF及NDF均較盤固草為低。尼羅草及盤固草割後4週的粗蛋白分別高於6、8 及10週。春、秋二季尼羅草的代謝能均高於盤固草，尤其割後6和8週再生植物體之代謝能較4及10週為高。經置於牛瘤胃消化72小時後再由顯微鏡觀察，發現再生8週的尼羅草的葉片、莖及盤固草的葉已被瘤胃微生物分解。組織切片顯示，尼羅草的莖組織較盤固草易被分解。綜合上述，尼羅草及盤固草在再生6週時，均具有高的代謝能，尼羅草較盤固草具較高的芻料品質且較易被消化。因此，在台灣尼羅草較盤固草更適合去飼養草食或反芻動物。

關鍵字

尼羅草 ； 盤固草 ； 消化率 ； 代謝能 ； 組織

並列摘要

Nilegrass (Acrocras macrum Stapf) and pangolagrass (Digitaria decumbens Stent.) are perennial C3 and C4 forage grasses, respectively. Both species produce high forage yield and fast regrowth after cutting in Taiwan. The objective of this study was to compare the chemical contents, i.e., metabolizable energy (ME), acid detergent fibre (ADF), neutral detergent fibre (NDF) and water soluble carbohydrate (WSC) and observe the changes in cell wall digestion of nilegrass and pangolagrass cut at 4, 6, 8 and 10 weeks after regrowth in spring and fall. The contents of ADF and NDF of nilegrass were lower than those of pangolagrass in both spring and fall. The contents of crude protein in nilegrass and pangolagrass cut at 4 weeks were higher than those cut at 6, 8 and 10 weeks, respectively. The ME of nilegrass was higher than that of pangolagrass in both spring and fall. Particularly, the ME of nilegrass cut at 6 and 8 weeks were higher than those cut at 4 and 10 weeks in both seasons. After 72 hours in the rumen observed by microscope, it showed that both stem and leaf of nilegrass up to an 8-week growth stage and the leaf of pangolagrass cut at 4 and 6 weeks had been digested by rumen microorganisms. However, the stem tissue of pangolagrass was mostly undegraded at 8 and 10 weeks growth stages. The results showed that both nilegrass and pangolagrass had the highest ME at 6-week growth stage. Further, nilegrass was higher forage quality and more easily digested than pangolagrass. It was suggested that nilegrass could be grown widely to replace pangolagrass used as the forage to feed herbivores or ruminants animals in Taiwan.

並列關鍵字

A crocras macrum ； Digitaria decumbens ； Digestibility ； Metabolizable energy ； Anatomy