The effect of bacterial inoculants on kikuyu silage quality

Abstract

SUMMARYTwo commercial bacterial inoculants (Lacto-flora and Ecosyl) were added to kikuyu grass (Pennisetum clandestinum) at ensiling, in 1985 and 1988 respectively, at Cedara, South Africa, using laboratory silos. In 1985 (Expt 1), Lacto-flora was added on its own and in combination with the enzymes Celluclast or SP249. In 1988 (Expt 2), Ecosyl was added on its own and in combination with molasses, at two levels of addition.The addition of Lacto-flora alone did not significantly increase the lactic acid bacteria or the lactic acid content of the treated silage. However, treated silage contained 53·6% less iso-butyric acid and 53·7% less ammonia than the control silage. Kikuyu silage supplemented with a combination of Lacto-flora and Celluclast or SP249 had higher numbers of lactic acid bacteria at ensiling (0·231 × 108/ml) than the control silage or silage receiving Lacto-flora alone. However, only silage supplemented with the combination of Lacto-flora and Celluclast had a significantly higher lactic acid content (2·23 compared with 0·04, 0·18 and 0·13% DM for the control silage, silages with Lactoflora and with a combination of Lacto-flora +SP249, respectively). Nevertheless, this silage contained 19·78% more acetic than lactic acid.Silage supplemented with Ecosyl on its own did not differ significantly in digestibility, loss of dry matter, ammonia, total non-structural carbohydrates, lactic acid and crude protein, from the untreated silage. A significant decrease in silage pH (from 5·08 to 4·70) was observed when Ecosyl was added together with molasses at the higher level of addition only. However, no other benefit was obtained by the addition of Ecosyl in combination with molasses.