The mineral content of some tropical forages commonly used in small ruminant production systems in the Caribbean – Part 2

Understanding the differences in the mineral concentrations of forages is critical as it informs on which and how species can be used to improve the mineral content of diets. Also, with the constantly changing nutritive value of forages, regulating the mineral composition through on-going forage evaluation is important as deficient minerals can be identified and supplemented. Therefore, the aim of this study was to provide information on the mineral profiles for 12 forage species used in small ruminant production systems in the Caribbean. The forage species included seven grasses ( Brachiaria arrecta, Brachiaria ruziziensis x), Cynodon dactylon, Cynodon, nlemfuensis, Digitaria eriantha, Megathyrsus maximus and Pennisetum purpureum ); two leguminous multipurpose tree species (LMPTs) ( Gliricidia sepium and Leucaena leucocephala ) and three non-leguminous multipurpose tree species (NLMPTs) ( Moringa oleifera, Morus alba and Trichanthera gigantea ). Overall, the calcium, phosphorus, magnesium, cobalt, manganese, and zinc were within the range required for small ruminants. Brachiaria arrecta and Digitaria eriantha were the only two species with Na concentrations that were within the range required for small ruminants (0.9626 and 4.4281 g/kg DM respectively). Brachiaria arrecta, Cynodon dactylon , Cynodon nlemfuensis , Leucaena leucocephala and Trichanthera gigantea were the only species with copper concentrations that were within the range required for small ruminants (11.50, 20.24, 11.95, 8.16 and 16.60 mg/kg DM). The concentration of potassium in Pennisetum purpureum (39.1 g/kg DM), Brachiaria arrecta (32.6 g/kg DM), and Cynodon nlemfuensis (34.0 g/kg DM), the concentration of iron in Cynodon dactylon (3340 g/kg DM) and molybdenum in both Cynodon dactylon (8.615 mg/kg DM) and Cynodon nlemfuensis (7.722 mg/kg DM) were above the maximum tolerable levels for small ruminants. The results of the study suggest that forages varied in mineral concentrations and the toxic and marginal concentrations of specific minerals in various forage species elicit the careful management of inclusion in diets, to ensure that the mineral concentrations are within the range required for small ruminants.