M. Tjandraatmadja et al., ENSILAGE CHARACTERISTICS OF 3 TROPICAL GRASSES AS INFLUENCED BY STAGEOF GROWTH AND ADDITION OF MOLASSES, World journal of microbiology & biotechnology, 10(1), 1994, pp. 74-81
When molasses was added during ensilage of three tropical grasses [ham
il grass (Panicum maximum cv. Hamil), pangola grass (Digitaria decumbe
ns) and setaria (Setaria sphacelata cv. Kazungula)] the final pH, conc
entration of fermentation acids (except lactic acid) and NH3-N content
were all similar after 100 days of incubation. Pangola grass silage h
ad significantly higher lactic acid content (66 g/kg dry matter) than
the other two. Adding either 4 or 8% (w/w) molasses reduced NH3-N, vol
atile fatty acid content and pH but increased lactic acid content in t
he final silages. Numbers of lactic acid bacteria remained approximate
ly constant during the course of the fermentation, although large diff
erences were noted in the species composition of the populations. At t
he time of ensiling, only Pediococcus spp. and Leuconostoc spp. were d
etected. By 5 days, the homo-fermentative population, notably Lactobac
illus plantarum, dominated (43%) and remained dominant. Hetero-ferment
ative rods were only detected in the 100-day silage, where they repres
ented 29% of the strains isolated. Homo-fermenters were more abundant
in pangola (60%) and setaria (47%) silages than hamil (27%) silages. H
omo-fermenter populations were lowest in the 12-week forage. Molasses
additions increased homo-fermenter populations. Pangola grass gave the
best quality silage but, since the water-soluble carbohydrate content
in the grasses was insufficient to promote a strong lactic fermentati
on, the addition of 20 to 30 kg molasses/tonne should achieve satisfac
tory preservation.