Comparative assessment on chemical compositions and feeding values of leaves of Moringa stenopetala and Moringa oleifera using in vitro gas production method

Evaluating the nutritional value of indigenous shrubs, trees and browse plants is important in Ethiopian situation where availability and quality of forages severely limited during long and dry seasons. A comparative assessment was thus conducted to investigate the nutrient compositions and feeding values of M. stenopetala and M. oleifera leaves. Feed samples were analyzed for proximate nutrients, minerals and amino acid profiles using official methods. In addition, the metabolizable energy (ME), organic matter digestibility (OMD) and short chain fatty acids (SCFA) were predicated using the Hohenheim in vitro gas test method. M. stenopetala had 26.6% crude protein (CP), 3.36% fat, 17.9 KJ/kg DM gross energy, 45% nitrogen free extract (NFE), and 38.4% non fiber carbohydrate (NFC). In M. oleifera, the contents of CP, fat, NFE, NFC and gross energy were 28.9%, 6.73%, 45%, 38.4% and 17.9 MJ/kg DM, respectively. M. stenopetala leaves contained significantly higher crude fiber, acid detergent fiber (ADF) and cellulose than those of M. oleifera. However, the acid detergent lignin (ADL) and hemicelluloses contents of M. oleifera were significantly higher than those of M. stenopetala. The contents of calcium, phosphorous, magnesium, potassium and sodium in M. stenopetala were 2.47%, 0.57%, 0.76%, 2.45% and 0.11%, respectively. The values of the corresponding minerals in M. oleifera were 2.62%, 0.43%, 0.56%, 2.0% and 0.03%. The concentrations of essential amino acids were significantly higher in M. oleifera than those of M. stenopetala and were generally comparable with the contents of soybean meal. The highest in vitro gas production of 47.9 ml was recorded for M. stenopetala, being significantly higher than for M. oleifera (40.6 ml). Similarly, values of ME (9.83 MJ/kg DM), OMD (76.4%) and SCFA (101 mmol) in M. stenopetala were significantly higher than those of M. oleifera. Although not significant, organic matter, CP, fat, ADF and cellulose contents were positively correlated with in vitro gas production while DM, NFE, neutral detergent fiber, ADL and hemicelluloses contents were negatively correlated with gas production. The chemical compositions showed the potential of leaves of both Moringa species to be used as a protein supplement in ruminant and non-ruminant feeding during the dry season. Moreover, the enhanced values of ME, OMD and SCFA in leaf suggest its ability to meet the energy requirements of tropical livestock.