As one of the most influential scientists of his generation, Peter Van Soest forever changed fiber analysis and the way we feed our cows. This Washington State dairy farm boy from humble immigrant roots created protocols for acid detergent fiber (ADF) and neutral detergent fiber (NDF). In doing so, he unlocked many of the mysteries involving lignin. Even though Van Soest recently passed away at age 91, his historic work with fiber digestion will live on for the ages in over 50 species, including humans.

A strikingly unique individual who ardently studied history and the periodic table as a youth, Van Soest immediately began challenging over 100 years of conventional wisdom surrounding crude fiber systems after arriving at the USDA’s Agricultural Research Service in 1964. While critics argued that chemical analysis of feeds was a conceptual dead end, the young scientist pressed on and shortly thereafter gave the world a way to precisely separate feeds into three important categories.

In transitioning to Cornell University four years later, Van Soest built upon the separation of forages into parts that were digestible to all animals, components that were indigestible without fermentation, and those components that were completely indigestible. All this work offered new ways to determine energy output of forages.

Even as Van Soest’s fame grew, he remained extremely approachable, speaking in over 30 countries and often holding informal gatherings with students at local venues to further improve feed analysis. As those conversations firmed up scientific theory, his work in fiber chemistry extended to human scientists studying dietary fiber’s impact on gut health and obesity.

Indeed, the boy who grew up at the foothills of the Cascade Mountain range, near the confluence of the Snohomish and Pilchuck Rivers, cast the longest of shadows on feeding and forages. The 24,000 citations for his signature work testify to the unquestioned fact that Peter Van Soest is the Father of the Fiber Revolution.