Nutrient compositions and in vitro methane production profiles of leaves and whole pods of twelve tropical multipurpose tree species cultivated in Ethiopia

Abstract

A screening study was conducted to investigate the nutrient composition, anti-nutritional factors, in vitro gas (GP) and methane (CH4) production of leaves and whole pods in tropical multipurpose trees (MPTs). The results indicated that the highest CP (296 g/kg DM) was found in Moringa stenopetala leaves followed by Acacia abysinica (277 g/kg DM), Millettia ferruginea (264 g/kg DM), Prosopis juliflora (261 g/kg DM) and Moringa oleifera (256 g/kg DM). In whole pods, the CP ranged from 172 in M. ferruginea to 191 g/kg DM in M. stenopetala. The starch in M. stenopetala, P. juliflora and Chamaecytisus palmensis leaves was 44.2, 28.8 and 24.4 g/kg DM, respectively. Leaves of Cajanus cajan had the highest concentrations of valine, isoleucine, leucine, phenylalanine, lysine and threonine. The highest concentration of total and tannin phenols were observed in leaves of A. nilotica while P. juliflora leaves had the lowest. Leaves of M. oleifera had higher total phenols and soluble condensed tannins than those of M. stenopetala. The in vitro GP were (P < 0.05) higher in leaves of Moringa species, Sesbania sesban, C. palmensis and Leucaena leucocephala than other MPTs. The CH4 production in A. nilotica, P. juliflora and C. cajan leaves was 1.05, −1.16 and 1.79 ml/200 mg DM, respectively and were lower (P < 0.05) than other MPTs. The lowest CH4 was observed in M. ferruginea pods (2.64 ml/200 mg DM) being (P < 0.05) different from other species. In conclusion, leaves of A. nilotica, P. juliflora, C. cajan and pods of M. ferruginea were identified as potential candidates in mitigating CH4 production and might be used as feed additives or supplementary feed for grazing ruminants.