The Macro-Mineral Profile of Four Tropicas Grasses at Different Stages of Regrowth

Pang°la grass (Digitaria decumbeas) , • Lucuntu grass (Ischaemum timorcnse) , Star grass (Cyilodon niemfuensis) and Tanner grass (Brachiaria radicans) were planted on Piarco fine sand soil at Central Experiment Station, Centeno, Trinidad, using a split plot design with grasses as main plots, and regrowth cutting intervals: 4,5,6,7 and 8 weeks as sub-plots, in order to study their effects on the macro-mineral profile of the grasses. There were four replicates per treatment. When gratlses were compared, it was found that there were significant (P .001) differences in overall means of nitrogen (N), calcium (Ca), phosphorus (P), sodium (Na) and magnesium (Mg) content, but not of potassium (K) content. Star grass had the highest levels (g/kg dry 48 matter) of N (12.8), P (3.4) and Mg (2.4); while Ca (7.3) and K (10.4) content were highest in Lucuntu grass. The lowest content of N (8.1) and Ca (2.8) were found in Tanner grass, of K (7.3) and Mg (1.6) in Pangola grass, and of P (1.8) and Na (0.4) in Lucuntu grass. .For all minerals studied except calcium, there were significant (13 ,001) differences at different stages of regrowth, with the highest levels at 4 weeks of age decreasing gradually to reach the lowest levels at 8 weeks. The results are discussed in consideration of meeting the macro-mineral requirements of ruminants for optimum health and production.