Assessment of Ensilability of Six Tropical Grasses Using Three Different Approaches

Assessment of Ensilability of Six Tropical Grasses Using Three Different Approaches

The preparation of well-preserved silages is considered increasingly important in the tropics and subtropics. In these regions silage production played a minor role in the past, as ensilability of tropical grasses is generally considered poor. In this study ensilability of six tropical grasses grown in the Paraguayan Chaco Boreal (Panicum maximum cv. Gatton, Cynodon plectostachyus, Cynodon sp. cv. Tifton 85, Digitaria eriantha var. pentzii, Panicum maximum cv. Tanzania and Digitaria milanjiana) was assessed in three different ways: (1) The chemical determination of the ratio between water soluble carbohydrates (WSC) and buffer capacity (BC), (2) the biological rapid fermentation assay using additives of sucrose and/or lactic acid bacteria inoculants, and (3) modelling of silage preparation in plastic bags. BC and contents of WSC were low. Therefore, without additives, acceptable ensilability was attained only with two grasses when previously wilted, while four grasses were poorly ensilable. When soluble carbohydrates and lactic acid bacteria were added, ensilability was enhanced. The rapid fermentation test applied in this study represents an easy to handle tool to asses ensilability of plants with different contents of fermentation substrates (WSC) and to investigate interactions between plants and a variety of epiphytic micro-organisms.