The potential role of Indigofera zollingeriana as a high-quality forage for cattle in Indonesia

Ownership of cattle in Indonesia is dominated by smallholder farmers, who rely heavily on low-quality mature grasses and crop residues as animal feed. Forage tree legumes (FTLs) provide a practical and profitable option for supplying nutrients limiting cattle growth and reproduction, especially during the dry months. Indigofera zollingeriana is a tall, high-yielding plant under investigation as feed, which can produce edible plant material exceeding 4 t dry matter (DM)/ha/harvest, when cut every 68 days. I. zollingeriana is adapted to a relatively wide range of climatic conditions and soil-types, with notable high tolerance of acidic soils. Forage quality is high, with high crude protein (265 g/kg DM average) and low fiber (367 g neutral detergent fiber/kg DM) concentrations and high in vitro DM digestibility (72.6%). It contains no identified anti-nutritional compounds but concentration of indospicine, a recognized toxic contaminant in some species of Indigofera, is currently unknown. Information on animal responses to feeding I. zollingeriana is limited, especially for cattle, but research suggests growth responses in goats are comparable with those for other available FTLs. Research to date suggests I. zollingeriana could be a valuable addition to FTLs currently available in Indonesia, especially for acidic soils, but further information is required on performance on saline soils, persistence under regular harvesting, indospicine status, acceptance by cattle and effects on their productivity.