To address the escalating challenge of food scarcity and the associated conflicts between human and animal consumption, it is imperative to seek alternative resources that can substitute for traditional feed. Non-grain feed (NGF) raw materials represent a category of biomass resources that are distinct from grains in their composition. These materials are characterized by their high nutritional content, cost-effectiveness, ample availability, and consistent supply, which contribute to their significant economic potential. Nonetheless, the extensive application of NGF is currently hindered by several limitations, including a high concentration of antinutritional factors, suboptimal palatability, and an offensive odor, among other shortcomings. The synergistic fermentation of probiotics and enzymes (SFPE) is an innovative approach that integrates the use of a diverse array of enzymes during the feed fermentation process, as well as various strains of probiotics throughout the feed digestion process. This method aims to enhance the nutritional value of the feed, diminish the presence of antinutritional factors, and improve the overall palatability, thereby facilitating the optimal utilization of NGF. This strategy holds the promise of not only replacing conventional feed options but also mitigating the pressing issue of grain scarcity. This paper delves into the practical applications of NGF and presents an overview of the latest research advancements in SFPE fermentation techniques, which can provide cutting-edge and valuable reference for researchers who devote themselves to research in this field in the future.

Hemp forage (HF) seems a suitable forage for ruminants for its high nutritional value and rich phytochemicals that exert health and growth-promoting activities. We investigated the effects of hemp-related phytochemicals on rumen and plasma metabolism using metabolome when partially substituting alfalfa hay with HF in goat diets. Numbers of differential metabolites linearly increased with increasing HF substituting rate, approximately 50% of which were phytochemicals. Metabolic pathway enrichment analysis showed that the inclusion of HF greatly promoted steroid hormone biosynthesis, one carbon pool by folate, and retinol metabolism pathways in both rumen and plasma, which are beneficial for promoting animal health and well-being and enhancing the quality of animal products. Some phytochemicals showed inhibitory activities on the growth of certain ruminal bacteria; meanwhile, the detected intermediate metabolites indicated degradation of the phytochemicals by ruminal microbes. These phytochemicals work individually and synergistically to alter ruminal and plasma metabolic pathways, thus exerting benefits in promoting the health and wellbeing of animals.