Buffer substances are commonly used in cattle nutrition. However, factors such as buffer type and amount added do not take into account the intrinsic buffering capacity of other dietary ingredients. Objective: to determine the buffering capacity (BC) of 25 commonly used energy and protein feedstuffs as well as additives, silages, and forage ingredients. Methods: BC was measured using the technique described by Jasaitis et al (1988). Results are expressed in milliequivalents of hydrochloric acid required to generate a unit change in pH in the original feed sample. Results: the results of this study are in agreement with those reported by other authors. Conclusion: protein feedstuffs resulted in the highest BC values, followed by forages, while energy ingredients showed the lowest results.