Introduction of Moringa oleifera to Sardinia: fodder traits for an agroforestry approach

Moringa oleifera Lam. (miracle plant, MO) is a fast-growing and drought-resistant medicinal tree, native to India and cultivated in semi-arid and arid regions worldwide. It belongs to the Moringaceae family and has gained attention for its medicinal properties based on local folk knowledge (Alegbeleye, 2018; Matic et al., 2018). Several studies have explored nutritional composition and bioactive compounds in different parts of the plant such as root, bark, leaf, flower, pod, and seeds (Dalei et al., 2016). Leaf contains high amounts of crude protein, vitamins, minerals, and fatty acids. MO can provide several times more protein than yogurt, calcium than milk, vitamin C than oranges, vitamin A than carrots, iron than spinach, and potassium than bananas (Gopalakrishnan, 2016). Moreover, MO seed oil is rich in unsaturated fatty acids (UFAs), with oleic acid comprising up to 70%, making it an excellent functional edible oil raw material (Wang et al., 2025). It has been reported that MO, as fodder tree, is well suited to the drained sandy or loamy soil with a slightly acidic to slightly alkaline pH and a rainfall of 250–3000 mm (Thumber et al., 2010). A valuable and interesting feature of MO is to produce and retain evergreen leaves during the Mediterranean dry season. Agroforestry represents a valid agroecological approach for adapting to climate change and contributing to mitigation through carbon sequestration, improving food security and income opportunities and providing ecosystem services (Quandt et al., 2023). Climate change may affect forage quality in different ways. It is expected that the ongoing climate changes in the Mediterranean basin will make arid regions drier and temperate regions wetter, which is likely to have a different impact on the distribution of vegetation (Sun et al. 2022). Browse forages and multipurpose trees are widely used in Southern Europe and Eastern Mediterranean region, to alleviate feed shortages and supply vital nutrients for growth and reproduction for ruminants during long and dry periods from late spring to autumn (Sulas et al., 2016). In the framework of the Moringa4 Future Food project (M4FF) funded by the Sardinia Region (Rural Development Program 2014-2020, sub-measure 16.1) and coordinated by the CNR ISPAAM of Sassari, this study aimed at evaluating the potential of MO as tree component of a Mediterranean agroforestry system intercropped with forage legumes. With the aim of increasing the green forage sources across seasons, the specific objective of our research was to investigate the chemical composition and bioactive compounds in different plant organs of MO. The research started in autumn 2024 in a field experiment located in a private farm in North Sardinia, on calcareous-sandy-clay-loam soils with pH 8, poorly endowed in N and P (0.50 g/kg and 0.64 ppm N and P2O5 respectively), and 1.4% OM. Bromatological analysis: biomass subsamples were harvested and oven-dried at 65° C until constant weight after separation into leaves (i.e. leaflets with petioles) and related young branches (thereinafterbranches). Dried sub-samples were ground to 1 mm screen to be analyzed for quality traits. Total N was determined by using Kjeldahl method (AOAC method 991.20) and crude protein (CP) was calculated by multiplying the N content by 6.25. Neutral, acid detergent fiber and lignin (NDF, ADF and ADL) were determined according to Van Soest et al. (1991) and ether extract (EE) using Soxhlet extraction (AOAC method 942.05). Ashes (ASH) were determined by a 3 h long dry oxidation at 550 °C in a muffle furnace (ISO 5984). Moreover, total digestible nutrients (TDN), digestible dry matter (DDM), dry matter intake (DMI), relative feed value (RFV) and net energy for lactation (NEi) were estimated based on the following equations (Lithourgidis et al. 2006): TDN = (-1.291 × ADF) + 101.35. DMI = 120 ⁄ %NDF dry matter basis. DDM = 88.9 - (0.779 × ­F, dry matter basis). RFV = ÝM × %DMI × 0.775. NEl = (1.044 - (0.0119 × ­F) × 2.205 Bioactive Compounds: after harvesting, fresh biomass samples were kept on ice and stored at −20 °C, until lyophilization. Methanolic extracts were analyzed for total phenolics (TotP) and total flavonoids (TotF). TotP of extracts were determined using the Folin–Ciocâlteau reagent, according to Re et al. (2019). Results were expressed as grams of gallic acid equivalent kg−1 dry matter (g GAE kg−1 DM). TotF were quantified by colorimetric assay using the AlCl3 method (Re et al., 2019) and were expressed as grams of catechin equivalent kg−1 dry matter (g CE kg−1 DM). Results: CP concentration was 20% in leaves and 8.0% in branches. In leaves, the percentages of NDF, ADF and ADL were 38.9, 22.5 and 9.5%, respectively, whereas in branches they were 54.2, 38.1 and 6.9%. Ash varied from 4.98 to 2.50 and EE from 9.46 to 6.96% in leaves and branches, respectively. The levels of TDN, DDM, DMI, RFV, and NEi also differed between leaves and branches. Leaves reached a RFV value of 175.9, which is indicative of a prime forage (Horrocks and Vallentine,999). Interestingly, the leaves exhibited levels of TotP and TotF of 120 g GAE kg⁻¹ DM and 20 g CE kg⁻¹ DM, respectively, which were similar or higher compared to the leguminous species sulla and subterranean clover (Molinu et al., 2024). Conclusion: Our results evidenced that MO can supply valuable green fodder, which represents a high quality and complementary resource in critical feeding periods for the extensive Mediterranean farming systems. Concurrently, other higher-valued products from MO biomass can be developed for nutraceutical and pharmaceutical sectors. Finally, an agroforestry approach is recommended for MO when introduced into Mediterranean farming systems.