The forage lignocellulosic complex is one of the greatest limitations to utilization of nutrients in fiber. Consequently, several technologies have been developed to increase forage fiber utilization by dairy cows. Physical or mechanical processing techniques reduce forage particle size and gut fill and thereby increase intake. Such techniques increase the surface area for microbial colonization and may thus increase fiber utilization. Genetic technologies such as brown-midrib mutants with less lignin have been among the most repeatable and practical strategies to increase fiber utilization, even though some brown midrib hybrids are prone to lodging. Several alkalis have been effective at increasing fiber digestibility. Among these, ammoniation has the added benefit of increasing the nitrogen concentration of the forage. However, none of these has been widely adopted due to the cost and the caustic nature of the chemicals. Urea treatment is more benign but it requires sufficient urease and moisture for efficacy. Ammonia fiber expansion (AFEX) technology uses high moisture and pressure to depolymerize lignocellulose to a greater extent than ammoniation alone, but it occurs in reactors and is therefore not usable on farms. Promising biological technologies for increasing fiber utilization such as application of exogenous fibrolytic enzymes, live yeasts and yeast culture have had equivocal effects on forage fiber digestion though recent meta analyses suggest their overall effects are positive. Non-hydrolytic expansin-like proteins have can synergistically increase fiber digestion by cellulase due to their ability to expand cellulose microfibrils. White-rot fungi are perhaps the biological agents with the greatest potential for lignocellulose deconstruction but several species also degrade easily digestible carbohydrates. Less ruminant nutrition research has been conducted on brown rot fungi that can deconstruct lignocellulose by generating highly destructive hydroxyl radicals. More research is needed to increase the repeatability, efficacy, cost-effectiveness, and on-farm application of technologies for increasing fiber utilization by dairy cows.