Seasonal variation in the anti-nutrient and mineral components of some forage legumes and grasses

This study was conducted in Nsukka, Nigeria to evaluate the effect of season of harvest (rain and dry) on the anti-nutrient and mineral components of four herbaceous legumes (Calapogonium mucunoides, Centrosema pubescens, Stylosanthes guyanensis and Pueraria phaseoloides) and four forage grasses (Panicum maximum, Pennisetum purpureum, Cynodon nlemfuensis and Andropogon gayanus). The grasses were analyzed separately from the legumes. A 2 × 4 factorial arrangement laid out in completely randomized design (CRD) was used. Species, season and their interaction significantly (P < 0.05) influenced the anti-nutrient and mineral concentrations in the forage grasses and legumes. The alkaloid, hydrogen cyanide (HCN), oxalate, phytate, saponin, tannin, nitrogen (N), phosphorus (P) and potassium (K) contents of the grasses and legumes were significantly (P < 0.05) higher during the rainy than in the dry season. The concentrations of N, P and K varied significantly (P<0.05) among the legumes and between the grass species. C. mucunoides harvested during the rainy season significantly yielded higher percentage N compared with other legumes while P. phaseoloides harvested during the rainy season which had higher concentration of K than other legumes in any season. P. maximum harvested during the rainy season significantly produced higher N content compared with other grasses in any season while P. purpureum harvested in the rainy season significantly gave higher percentage of K and P compared with other grass species in any season.Keywords: Alkaloid, hydrogen cyanide, oxalate, saponin, tannin, minerals, grasses legumes, seasonAfrican Journal of Biotechnology Vol. 12(2), pp. 142-14