Dr. Hristov gave a webinar titled “Histidine: a limiting amino acid for dairy cows” on March 4, 2025, and joins the podcast in this episode for a deeper dive into the topic. Panelists introduce themselves and give some background on their interest in histidine (00:52) Dr. Hristov gives an overview of his webinar presentation, touching on some of the first research projects that showed lower protein diets resulted in no change in plasma methionine, but a decrease in plasma histidine. When dietary protein decreases, the cow relies more on microbial protein to meet her needs. Histidine content is about 20% less than methionine content in microbial protein. He also notes there are some short-term reserves of histidine in the body, so short-term studies may not show a histidine deficiency when indeed there is one. (7:08)