Dietary fiber from wood lignocellulose is emerging as a versatile, insoluble fiber source for poultry, swine, dogs, and other species. Composed of cellulose, hemicelluloses, and lignin, it modulates gut development, digesta kinetics, and microbiota without adding metabolizable energy. In poultry, moderate inclusion improves gizzard function, performance, and fecal characteristics; in swine, it eases farrowing and enhances piglet vitality. Canine studies indicate multifunctional benefits. Wood lignocellulose is available in tailored compositions for specific applications. This review summarizes species-specific responses, practical inclusion ranges, and research gaps for cross-species use.