Fermentation characteristics and changes in nutritive value of guinea grass-leucaena ensiled with or without additive

Abstract

Fifty-two-day-old guinea grass (Panicum maximum var. maximum cv. Gatton) which received 150 kg N per hectare and 10-month-old leucaena (Leucaena leucocephala (Lam.) De Wit.) were used. There were five treatments viz., guinea grass (T1), leucaena (T2), guinea grass-leucaena (T3), guinea grass-leucaena with starch (T4) and guinea grass-leucaena with formic acid (T5). Both guinea grass and leucaena were mixed in a grass:legume ratio of 7:3 in T3, T4 and T5. Samples were stuffed into laboratory silo (1.4-1.5 kg sample) and stored for 42 days. Samples were taken at and after ensiling and analysed for total nitrogen, volatile basic nitrogen as per cent of total N, pH, lactic acid, acetic acid, butyric acid, neutral detergent fibre (NDF), acid detergent fibre (ADF), cellulose, acid detergent lignin (ADL) and in vitro dry matter digestibility (IVDMD). Guinea grass had significantly lower (P<0.01) nitrogen content but higher content of fibre compared to leucaena. The IVDMD values (50%) were similar (P<0.05) in both guinea grass and leucaena. Combining guinea grass with leucaena significantly (P<0.05) raised the nitrogen content of the mixture but slightly reduced the cell wall components. It also raised the IVDMD value (54 per cent) though not significantly. Addition of starch reduced the nitrogen content and the cell wall consistency but increased the IVDMD value (56 per cent). These changes were significant (P<0.05). Guinea grass silage had a significantly (P<0.05) lower pH and volatile basic acid (VAN) than leucaena. Guinea grass with leucaena starch had the lowest pH but was not significantly different from T1, T3 and T5. The lactic acid content of T4 was significantly higher (P<0.05) than the others. T5 has the lowest VBN.


(Ghana Journal of Agricultural Science, 1996, 29(2): 99-106)