Solid-State Fermentation of Crop Residues and Agro-Industrial Byproducts in Small Ruminant Production: A Review

The increasing competition for major feed ingredients such as maize due to world crisis, caused by the high cost and scarcity of these conventional feed ingredients due to climate changes have necessitated the exploration of indigestible alternative feed resources for sustainable small ruminant production. Crop residues and agro-industrial by-products (AIBPs) are highly abundant, cost-effective, and readily available feed options that can enhance livestock production while minimizing environmental waste. This systematic review evaluates the nutritive effects, physiological responses, and reproductive parameters associated with the inclusion of crop residues and AIBPs in small ruminant diets. The review synthesizes findings from various studies, highlighting their impact on feed intake, digestibility, growth performance, haematological and biochemical indices, reproductive efficiency, and overall productivity. While these alternative feed resources can improve nutrient availability and animal performance, challenges such as anti-nutritional factors and variability in nutrient composition must be addressed through appropriate processing techniques. The findings suggest adequate utilization of crop residues and AIBPs, alongside suitable supplementation, did not necessarily affect the production indices, thereby enhancing small ruminant production, reduce feeding costs, and contribute to sustainable livestock farming as well as decrease the potency for environmental pollution.