
This episode of the Real Science Exchange features Dr. Mary Beth Hall, founder of The Cows Are Always Right and former USDA‑ARS scientist, discussing her highly attended Real Science Exchange webinar, Manure Evaluation: Figuring Out What’s Going On Between Cows and Their Rations. Joining the pub‑table conversation are Dr. Clay Zimmerman, Dr. Stefano Vandoni, and Dr. Sion Richards. Dr. Mary Beth Hall explains why manure evaluation is one of the most reliable diagnostic tools in dairy nutrition, providing a direct biological response that may not appear in ration models or performance data. She emphasizes why manure must be evaluated alongside cow behavior and production metrics. (09:28) Mary Beth breaks down the science of fecal pH, including how to measure it correctly, why results can be misleading if done improperly, and what fecal pH reveals about digestion beyond the rumen. She explains why fecal pH does not directly reflect rumen pH and how fiber source influences hindgut fe...