Macro mineral and trace element content of pangola grass and other forages in Guadeloupe (F.W.I.)

Abstract

Macro minerals and trace elements of ruminant feeding interest were determined in forages from three regions of Guadeloupe (French West Indies) region A - calcareous area with Vertisols overlying coral limestone with a marked dry season; region B - acid soils area with Vertisols and Oxisols and a mild dry season; region C - ferrallitic soils area (Oxisols) with a short dry season. Samples of pangola grass and natural pastures were collected at five locations within each region, during both the rainy and dry seasons, at two stages of regrowth (28 vs. 42 d). The region of sampling and the type of forage were the main sources of variation of the macro mineral and trace element content of forages. The samples of pangola grown in calcareous regions had lower concentrations of phosphorus, magnesium, copper, zinc, manganese, and selenium than samples collected in other regions; region A - 2.18 g P/kg DM, 1.49 g Mg/kg DM, 6.75 mg Cu/kg DM, 26.82 mg Zn/kg DM, 53.00 mgMn/kg DM, 0.11 mg Se/kg DM; region B - 3.31 g P/kg DM, 1.51 g Mg/ kg DM, 8.75 mg Cu/kg DM, 50.40 mg Zn/kg DM, 226.00 mg Mn/kg DM, 0.17 mg Se/kg DM; region C - 2.73 g P/kg DM, 1.45 g Mg/kg DM, 7.69 mg Cu/kg DM, 32.75 mg Zn/kg DM, 284.00 mg Mn/kg DM, 0.15 mg Se/kg DM. Phosphorus, copper, zinc and selenium contents of forages were frequently below critical nutritional values in each region of sampling. Natural savana forages presented lower phosphorus, magnesium, sodium, copper and zinc contents than those of pangola. The risks of deficiencies in phosphorus, copper, zinc and selenium for the grazing ruminant in the different regions of Guadeloupe are discussed.