A collective noun for Mares is a stud. A stud is a group of Mares that are kept together for breeding purposes. The term “stud” is derived from the Old English word “stod”, which means a group of horses. This term was used to refer to a group of horses kept together for breeding purposes, and eventually came to refer to a group of Mares specifically.
What Is a Group of Mares Called? – Mares Collective Nouns.
