Neglected grass species of Southern Africa: Nutritive value of conserved <i>Hyperthelia dissoluta</i> harvested at different growth stages

Abstract

Native species like Hyperthelia dissoluta have great potential in livestock production but not much has been done to improve their contribution to that sector. This study examined 2 conservation methods (drying and ensiling) and 3 different growth stages, namely: elongation stage (January), early flowering (February) and late flowering stage (March) of H. dissoluta in terms of nutritional composition and digestibility. The method of conservation had a significant effect (P<0.05) on nutritive value, with silage having more P and CP than hay. Stage of growth had an effect (P<0.05) on all nutritional properties of both hay and silage: Phosphorus, Ca and CP concentrations and digestibility of hay and silage decreased with maturity, while NDF and ADF concentrations increased. Silage pH value was significantly higher at elongation (5.2) and late flowering growth stages (5.7) than at early flowering (4.4). Dry matter digestibility of the conserved material reached levels as high as 82% for silage made at the elongation stage with all values at least 60%. We conclude that H. dissoluta can be conserved as both silage and hay to produce a good quality feed. Harvesting at the early flowering stage would seem to provide a good compromise between quantity (not measured in this study) and quality of harvested forage. Further studies seem warranted to determine the acceptability and intake of the material by livestock, the advantages of adding fermentable carbohydrates during ensiling and DM yields in different areas and a range of seasonal conditions. Keywords: Air drying, hay, perennial native grasses, plastic bag silo, quality silage.DOI: 10.17138/TGFT(4)179-184