A Comprehensive Review on the Valorization of Agricultural By-products for Sustainable Ruminant Production in Nigeria

Agricultural by-products and residues in Nigeria are a huge untapped resource that has the potential to improve sustainable ruminant production and reduce environmental pollution. This review aims to compile the latest developments in the utilization of different agricultural by-products such as maize husks, rice straw, cassava peels, groundnut husks, and sugarcane bagasse, based on their proximate composition, nutritional value, and potential use as feed supplements. The review discusses the valorization of these agricultural by-products as a sustainable approach for improving ruminant production in Nigeria. The review also discusses the recent biotechnological and nanotechnological approaches for upgrading agro-waste into value-added products for improving feed efficiency, animal health, and production sustainability. We synthesize the existing literature to compile the major by-products available in Nigeria and processing by-products account for their nutritional composition, availability, and disposal. The paper critically reviews different valorization approaches, such as physical, chemical, and biological processes to improve the nutritional value and palatability of these fibrous materials. In addition, we review the effects of supplementing these processed and unprocessed by-products to ruminants on feed intake, digestibility, growth, and milk production. Challenges such as infrastructural deficiencies, policy, and research investment that limit effective valorization in Nigeria are also reviewed. The review concludes that the valorization of agricultural by-products is a viable, sustainable, and economically sound approach to address feed insecurity, environmental waste, and the sustainability of the ruminant production system in Nigeria. This synthesis offers a contemporary knowledge base to guide researchers, policymakers, and stakeholders in optimizing agricultural by-product utilization for sustainable ruminant production in Nigeria.