Comparative studies on the yield of some herbaceous legumes and effects of storage on the quality of their pellets

Abstract

Dry matter yield of herbaceous legumes and effects of storage length of their pellets on the chemical composition were investigated. A two phased field and laboratory experiment were conducted. In the first experiment, the yield of the forage legumes using a 5 x 2 factorial experiment consisting of five herbaceous legumes (Lablab purpureus, Mucuna pruriens, Centrosema molle, Centrosema pascorum and Calopogonium mucunoides) and two harvesting ages (6 and 12 weeks after sowing) laid out in a split-plot design was determined. The second experiment was the selection of herbaceous legumes with higher yields from Experiment 1 using a 3 x 4 factorial experiment consisting of the three herbaceous legumes (L. purpureus, C. mucunoides and M. pruriens) used to make pellets and four storage lengths (0 i.e. fresh, 30, 60 and 90 days). Treatments in both experiments were replicated three times. Results showed that legumes harvested 12 weeks after sowing (WAS) had significantly (P < 0.05) higher dry matter yield (2.73 t ha^-1) than legumes at 6 WAS, while Lablab purpureus produced the highest (P < 0.05) dry matter yield (2.94 t ha^-1) of the legumes evaluated.. The physical characteristics of the herbaceous legumes pellets such as colour, odour and moldiness at different storage length showed that they were between fair and good pellets. The L. purpureus and M. pruriens had higher (P < 0.05) CP content than C. mucunoides. Differences in the CP content of pellets with the storage lengths employed was not significant (P > 0.05). Higher oxalate, phytate and saponin contents were found in C. mucunoides pellets than in other legumes pellets while the tannin content was in the order of M. pruriens (43.63 mg kg^-1) > L. purpureus (26.00 mg kg^-1) > C. mucunoides (20.31 mg kg^-1). In conclusion, increasing age at harvest increased the yield of the legumes, while increasing storage duration decreased the CP content but increased the NDF, ADF and saponin content of the pellets.