Plant bioactive compounds (PBCs) as functional feed additives for improving livestock and poultry production

The use of antibiotics to promote growth and prevent disease in livestock and poultry animals has raised concerns about antimicrobial resistance and its consequences for public health. Increasing pressure on the livestock and poultry industries demands improved productivity, reduced economic losses, and the assurance of food safety for human consumption. Plant bioactive compounds (PBCs) have emerged as safe and sustainable alternatives to antibiotics that promote the growth, support animal health and improve productivity without compromising food safety. PBCs represent a diverse group of secondary metabolites-including phenolics, terpenoids, polysaccharides, and organosulfur compounds-that exhibit a wide range of biological activities relevant to livestock and poultry nutrition and health. Recent studies have shown that supplementing animals with PBCs as feed additives, either as crude extracts or individual compounds, improves growth performance, nutrient utilization, and modulates gut microbiota, while also exerting antioxidant, anti-inflammatory, antimicrobial, and immunoregulatory effects, thereby enhancing overall resilience of animals. The multifunctional properties of PBCs, and the reduced risk of resistance development position them as promising candidates for next-generation feed additives for livestock and poultry production. However, challenges remain regarding optimal concentration, variability in bioavailability, stability during feed processing, and the standardization of active components. Here, we discuss the major PBCs and their potential as functional feed additives to improve livestock and poultry production. We further highlight research gaps and outline future prospects required to advance their adoption in sustainable animal production.