Ensiling characteristic and nutritive value of Napier grass (Pennisetum purpureum Schmach) combined with or without leucaena (Leucaena leucocephala (Lam.) De Wit) as influenced by starch or formic acid addition

Abstract

About 12-week-old napier grass Pennisetum purpureum Schumach) and 10-month-old Leucaena (Leucaena leucocephala (Lam.) de Wit.) both from a naturalized field and chopped to about 3.5 cm were used. The grass and legume were combined in a grass:legume ratio of 7:3. There were five treatments viz., napier grass (T1), leucaena (T2), napier grass-leucaena (T3), napier grass-leucaena with starch added (50 g starch/kg fresh mixed forage) (T4) and napier grass-leucaena with formic acid added (2.3 ml per kg fresh mixed forage) (T5). Each of the treatment sample was stuffed into a two-litre laboratory silo (1.4-1.5 kg sample) and stored for 42 days. Samples were taken at the time of silo filling and after ensiling and analyzed for total nitrogen (T-N), volatile basic nitrogen (VBN) as per cent of total N, neutral detergent fibre (NDF), acid detergent fibre (ADF), cellulose, acid detergent lignin (ADL) and in vitro dry matter digestibility (IVDMD). Napier grass (T1) had significantly lower (P<0.01) T-N but higher cell wall components exc ept for ADL compared to T2. The IVDMD of T1 was significantly higher (P<0.05) than that of T2. Combination of napier grass with leucaena increased the T-N but reduced the fibres. Treatments T4 and T5 significantly differed (P<0.05) in T-N, cell wall components and IVDMD from each other. TreatmentT2 had a significantly higher (P<0.05) pH than the others. Lactic acid was signficantly developed in T4. Only T3 had some butyric acid. Treatment T4 had the lowest VBN. NDF in all silages slightly decreased while ADF, cellulose and ADL in some cases slightly increased. IVDMD slightly decreased or remained unchanged on ensiling.


(Ghana Journal of Agricultural Science, 1996, 29(2): 21-26)