Harnessing bush-based feed for ruminants in Namibia: challenges and opportunities—a review

Bush encroachment is a huge ecological and economic threat to Namibian rangeland ecosystems, significantly reducing rangeland biodiversity, productivity and threatening livestock production. However, encroacher bush biomass presents an opportunity for sustainable livestock feed, especially during the dry season when conventional feed resources are scarce and of poor quality. This review summarises existing knowledge and explores the potential of encroacher bush-based feed as a sustainable alternative to conventional feeds. Major constraints hampering its utilization and the opportunities to address feed shortages while simultaneously managing bush encroachment in the midst of climate change have been discussed. Milled bush biomass contains moderate to high levels of crude protein and fiber, varying by species and season The crude protein content of milled bush biomass varies from 46.9 to 111,8 g/kg DM. It contains substantial amounts of neutral detergent fibre, acid detergent fibre and acid detergent lignin, ranging from 594.3 to 734.3, 463.2 to 579.9 and 137.5 to 222.8 g/kg DM, respectively. Main challenges are variable nutritional quality of bushes, technical and financial challenges of harvesting and processing of bushes and limited skills on feed formulation. Opportunities lie in the integration of bush thinning with climate-smart livestock management, reduce feed shortages, improve livestock productivity, the development of cost-effective milling technologies, economic development and improved livelihood. Additionally, partnerships between research institutions, government agencies, and farmers can enhance knowledge transfer and improve feed formulation strategies. By addressing the challenges, Namibia can leverage bush-based feed to improve livestock productivity and promote rangeland restoration to support food security and livelihoods in changing climatic conditions.