Walter L. Hurley is a Professor Emeritus in the Department of Animal Sciences at the University of Illinois in Urbana, Illinois, USA. His research has focused on a broad range of topics related to the biology of lactation and his studies have examined aspects of comparative milk composition, immunoglobulin transport through colostrum, lactation physiology, and mammary gland development, function and involution in cattle and swine. At the University of Illinois, he teaches courses on lactation biology, handling of domestic farm animals, and student discovery of careers in animal sciences. He has been a recipient of a number of recognitions for his teaching, and has shared his experience and knowledge of concepts of teaching and learning with many national and international audiences. His online, open access Lactation Biology course (Coursera, Lactation Biology) includes over 120 short videos, offering learners fundamental information about the biology of lactation and how the mammary gland develops and functions.